GeoBytesGCSE

GEOBYTES GCSE - OCR A Revision Blog

2010-05-16T08:40:00.000-07:00

This blog is to support Year 11 students at St Ivo School currently preparing for the OCR A Geography GCSE.

To access summary notes and revision resources for each unit of the GCSE course, please follow the links below.

Unit 1 - People and the Physical World

Unit 2 - People and the Human World

Unit 3 - People and their Needs

Unit 4 - People and their Environment

Unit 1 - People and the Physical World

2010-05-16T08:24:00.000-07:00

UNIT 1 - PEOPLE AND THE PHYSICAL WORLD

Topic 1 - Plate Tectonics

Plate Tectonics - An Introduction
Plates and Convection Currents
Plate Boundaries
Volcanoes
Volcano Case Study - Mount St Helens - 1980
Living with Volcanoes
Volcanoes - Prediction Technology and Satellite imagery
Earthquakes
Earthquake Case Study - 1989 San Francisco Earthquake
Preparing for Earthquakes
Case Study of an Earthquake - LEDC - Bam 2003
Comparing Earthquakes
Plate Tectonics Revision

Topic 2 - Rivers and Flooding

The Hydrological Cycle
The Drainage Basin
Rivers - Source to Mouth
River Processes
Upper Course of the River Valley - V shaped valleys
Upper Course of the River - Waterfalls
Middle Course of the River - Meanders and Ox-bow lakes
Lower Course of the River - Floodplains and Levees
Hydrographs and River Discharge
Flooding in an MEDC - The Lynmouth Flood OR The Boscastle Flood
Flooding in an LEDC - Bangladesh
Comparing Flooding in an MEDC and LEDC
Rivers Revision

Topic 3 - Coasts
Coasts - Energy at the Coast
Coastal Processes - Erosion, Transport and Deposition
Coastal Erosion Landforms - Features and Formation
Coastal Deposition Landforms - Features and Formation
Case Study of Coastal Erosion - Dunwich (Suffolk)
Coastal Defence
Coasts Revision

INTERACTIVE REVISION RESOURCES
Practice Paper - Unit 1 People and the Physical World

Back to Index Page

Unit 2 - People and Places to Live

2010-05-16T08:16:00.000-07:00

UNIT 2 - PEOPLE AND PLACES TO LIVE

Topic 1 - Population
Entries for Population to be added as soon as possible

Topic 2 - Settlement
People and Places to Live - Settlement
Settlement - Site and Situation
Urban land-use models
Urban land-use zones 1 - The CBD
Urban land-use zones - Managing problems in and around the CBD
Urban land-use zones 2 - The inner city
Inner Cities - Solving the Problems: Urban Renewal
Inner Cities - Case Study - Regeneration of the London Docklands
Urban land-use zones 3 - Suburbs - the growth and characteristics of
Urban land-use zones 4 - The Rural Urban Fringe (land-use conflicts)
Out of Town Shopping Centres
Green Belts - controlling urban sprawl
Counterurbanisation - Causes and Consequences
Second Homes - Social and Economic Impacts
Settlement Hierarchies
The Interdependence of Settlements - Case Study - St Ives and Surroundings

INTERACTIVE REVISION RESOURCES:

Settlement Revision
Practice Paper - Unit 2 - People and Places to Live

Back to Index Page

Unit 3 - People and their Needs

2010-05-16T08:08:00.000-07:00

Unit 3 - PEOPLE AND THEIR NEEDS

TOPIC 1 - Quality of Life

Case Study of Rapid Economic Growth - South Korea
(More notes to come soon)

TOPIC 2 - Economic Activities

Farming - An introduction to Farming - The Farming System
Case Study of Commerical Farming in the UK - Cereal Farming in East Anglia
Changes in Farming in the UK
Case Study of Subsistence Farming - Rice Farming in India
Changes in Farming in India - The Green Revolution
Case Study - Manufacturing Industry - The Whitbread Brewery
Case Study - Distribution Industry - The Argos Distribution Industry
A Case Study of tourism in an LEDC - Kenya
A Case Study of tourism in an MEDC - Menora

TOPIC 3 - Energy

Non-Renewable Energy Sources (Coming soon)
Renewable Energy Sources (Coming soon)
Changing Energy Use in the UK (Coming soon)
The Nuclear Debate
Case Study of a nuclear disaster - Chernobyl (Coming soon)
The Impact of Changing Energy Sources on a Local community

Practice Paper - Unit 3 - People and their Needs

Back to Index Page

Unit 4 - People and their Environment

2010-05-16T08:05:00.000-07:00

UNIT 4 - PEOPLE AND THEIR NEEDS

Topic 1: Resource Development and the Local Environment

Limestone Quarrying in the Peak District National Park
Tropical Rainforests (Coming soon)
Deforestation in the Amazon Rainforest (Coming soon)
Consequences of Deforestation (Coming soon)
Sustainable use of Rainforests (Coming soon)
National Parks in the UK - the Peak District National Park (Coming soon)
Conflicts of Land-use in the Peak District National Park (Coming soon)
A Case Study of Water Pollution - The Sea Empress Disaster (Coming soon)

Topic 2: The Global Environment
Global Warming - Causes of (Coming soon)
Global Warming - Consequences of (Local and Global) (Coming soon)
Global Warming - Tackling the Issue (Coming soon)
Acid Rain - Causes and Consequences of (Coming soon)
Acid Rain - Tackling the Issue (Coming soon)

Back to Index Page

A Case Study of Tourism in an LEDC - Kenya

2008-04-29T05:24:00.000-07:00

Where is Kenya?

Kenya is located in East Africa, its capital city is Nairobi and it has a population of approximately 30 million people.

Why visit Kenya?

- it has an attractive climate (tropical) with sunshine all year round, hot and humid at the coast; temperate inland and dry in the NE (rainy season - April-June and Oct-Dec, heavy rainfall in the afternoon and early evening)

- Safari holidays are popular - e.g. in the Maasai Mara / Nakuru National Park - Kenya has spectacular wildlife - including the big 5 - Lion, Elephant, Rhinoceros, Leopard and Buffalo

- Cultural experience - many tourists visit local tribes such as the Maasai to find out more about their lifestyle and traditions

- Coastal Holidays - SE of Kenya has fine sands and coral reefs with spectacular marine life - e.g. Mombassa

Why have numbers of tourists visiting Kenya increased?

- Kenya was one of the first LEDC countries to acheive mass tourism and in the 1970s and 1980s there was a rapid increase in the numbers of tourists, particularly following the release of the films Born Free and Out of Africa.

- Tourist numbers have also increased as larger aircraft in the 1980s brought prices of air travel down.

Advantages of Tourism to Kenya:

- Tourism encourages the building of new roads and better communications
- Jobs in tourism have helped develop people's business skills
- Tourism has created all year round jobs for Kenyans
- Tourism is Kenya's biggest earner of foreign exchange
-Tourism has stimulated farming, by creating a demand for local food from farmers
- National Parks have been created - encouraging people to protect the environment.

Disadvantages of Tourism for Kenya:

- there is leakage of income - with a lot of the money paid for holidays never actually reaching Kenya (travel companies and foreign owned hotels get it instead)

- Safari minibuses disturb animals - often getting too close (e.g. can be 30-40 buses around a single animal in the Maasai Mara), they also cause soil erosion as the wheels churn up the grass

- many Maasai are traditionally nomadic, but many have been forced out of the National Parks - losing their land and also losing their traditional lifestyles.

- Hot air balloons in parks disturb animals - by casting shadows and from the noise of the burners.

- Coastal Environments such as those in Mombassa have been damaged - e.g. destruction of coral reefs as tourists step on the coral and also take souvenirs.

- Drugs and crime has increased and AIDS is a major problem

Working towards sustainable tourism in Kenya - KIGO CONSERVANCY - An example of ECOTOURISM.

Kigio Conservancy was set up in 1997 on an old beef / dairy ranch with the aim of providing a wildlife sanctuary and a sustainable eco-tourism destination.

The accommodation at Kigio is in "cottages" built of mud, timber and thatch, using local and reclaimed materials and methods. The furniture is built from re-claimed timber from the ground and there is no electricity, oil lamps are instead used.

Kigio has a number of ecotourism activities it is involved in:

- partnerships with local communities - helping to fund and work on community projects
- provides links with local schools with schools in the UK, raising money for new classrooms and other projects (e.g. water tanks)
- partnerships with conservation organisations such as the Tusk Trust - which has involved setting up conservation centre for use by local schools and providing sustainable development education for local communities
- employees local people - e.g. guides and other workers
- conservation activities - e.g. looking after orphaned wildlife - e.g. 2003 relocation of giraffe into the area - including a baby giraffe from the Karen Blixen Giraffe Orphange in Nairobi.

Links:

Kigio Conservancy Centre - External Link
Tourism in Kenya - Kenya Web - External Link

A Case Study of Tourism in an MEDC - Menorca

2008-04-29T05:23:00.002-07:00

Menorca is the second largest of the Spanish Balearic Islands in the Mediterranean Sea. It has a population of 67,000 and it has a total land area of 702km2.

Reasons why people visit Menorca:

- Mediterranean Climate - average temperature of 16oC with an average of 24oC in the summer months and little rainfall in the summer
- Menorca has a beautiul and varied landscape - Northern Menorca has an uneven and rugged coastline and in the south there are many white sandy beaches
- There are a wide range of watersports available (windsurfing; water skiing, scuba-diving etc.)
- Other outdoor activities include horse riding, cycling and potholing.

What are the advantages of tourism to Menorca?

- Job creation - tourism is the largest employer in Menorca
- tourism has had a multiplier effect and helps to support many different sectors of the economy e.g. jobs in farming (providing food for hotels and cafes), jobs in the craft industry (providing locally made souvenirs) and it is recognised that ice-cream is a major business
- tourism in Menorca has also raised awareness of the need to preserve the environment

What are the disadvantages of tourism to Menorca?

- as tourism is very much a seasonal industry - employment fluctuates at different times of the year
- the demands of the tourists have led to changes in the local way of life and there is also resentment of the number of villas and other properties being bought up as second homes by foreigners
- some of the earliest hotels which were built did not fit in with the local landscape and contrast dramatically against the beauty of the natural coastline
- the local culture has suffered some 'erosion' as changes have been made to meet the demands of tourists

Working towards more sustainable tourism in Menorca

In recognition of the importance of tourism to Menorca, as well as the importance of protecting the natural landscape which attracts tourists in the first place there have been increasing attempts in Menorca to make tourism more sustainable. These attempts include:

- the UN have declared the island a Biosphere Reserve with the aim of continuing to profit from tourism in Menorca whilst also protecting the island
- as part of the Biosphere - urban development has been controlled and beaches have been managed
- endangered species have been protected
- education programmes have been adopted in schools to raise environmental awareness
-tight planning controls have been implemented on the island restricting the growth of multi-storey hotels within 250km of the coastline to conserve the natural beauty of the landscape.
- government attempts to protect the impact on the local culture includes ensuring that all signage is in the traditional Menorqui language.

Photo Credits: http://www.flickr.com/photos/gerriet/

Tourism - An Introduction

2008-04-29T05:23:00.001-07:00

Tourism is a tertiary industry in which services are provided. The industry depends on people and governments having money to spend. Tourism has become one of the world's fastest growing industries, it is an important part of the economy in MEDCs and for many LEDCs, tourism has enabled rapid economic development.

Why has the tourism industry grown?
1. People have more disposable income
2. Falling prices and the development of budget airlines - e.g. Ryanair means that holidays are more affordable
3. People have more leisure time
4. Air travel has made it easier to travel to more distant places.

Although tourism brings many advantages to a country, it also brings disadvantages.

For the OCR A course you need to learn 2 case studies of tourism
1. Tourism in an LEDC - Kenya
2. Tourism in an MEDC - Menorca

We have also studied tourism in the Peak District National Park.

For each case study you need to learn:
1. Why do tourists visit the destination - human and physical attractions?
2. What are the positive and negative impacts of tourism?
3. What management techniques can be used to make tourism in the destination more sustainable?

Quarrying in a National Park

2008-04-29T03:37:00.000-07:00

Quarrying is...
the extraction of rocks and other materials from the earths surface through blasting. Frequently quarried materials include sand, gravel, limestone etc.

Limestone Quarrying in the Peak District
The Peak District is a major area of limestone quarrying, including works at Hope Quarry and Wirksworth Quarry.

Hope Quarry is located close to Castleton. It began extraction in 1948, just before the area was designated a national park. 2 million tonnes of limestone are extracted each year, used to produce 10% of the UK's cement.

How is limestone quarried?
- these quarries are often deep and dug on several levels
- controlled explosions are used to blast rock from the ground
- rock is then taken to a crusher where it is broken down into smaller pieces

What is limestone used for?
- aggregate or crushed rock
- building purposes
- cement production
- chemical production - fertiliser etc.
- iron and steel
- lime

Advantages of Quarrying
- creates job opportunities (10% of male employment in the Derbyshire Dales is in Quarrying and 300 people are employed at Hope Quarry).
- multiplier effect, created by creation of jobs, more money in the area and more services supported
- great demand for limestone for building purposes as well as other products such as cement .
- it is a raw material needed to support both the local and national economy
- roads improved to cope with the large lorries (benefits the local community)
- the quarry provides a source of money for the local council through taxes and rates

Disadvantages of Quarrying
- blasting for quarrying releases large amounts of dust (problem for asthma sufferers and pollutes water supplies)
- leaves an ugly scar in the land when abandoned (an eyesore)
- heavy lorries transporting limestone cause congestion on narrow roads and increase the likelihood of accidents
- wildlife and habitats are destroyed and lost
- noise pollution from the blasting disturbs both wildlife and local people
- heavy lorries cause more frequent costly repairs to roads to be made.

What can be done to reduce the problems associated with quarrying?
1. Earth Mounds - this are built around the quarry to reduce the impact of noise from blasting on the local area
2. Water sprays - these can be used to reduce the spread of dust from the quarry
3. Restrictions are put on the size of the quarry that is allowed
4. Blasting is only allowed during designated areas to minimise impact on locals
5. Quarry's are often screened off e.g. by trees etc.. to reduce visual impact
6. Restoration plans are often put in place following the decommissioning of a quarry - examples have included the development of wetland habitats, lakes and other conservation / recreation areas.

Links:

Mineral extraction in the Peak District National Park - External Link http://www.peakdistrict-education.gov.uk/Fact%20Sheets/fz11mex.htm

Limestone in the Peak District National Park - External Link http://www.peakdistrict-nationalpark.info/place/limestone/index.html

The Impact of Changing Energy Sources on a Local Community - Holmewood

2008-04-29T03:24:00.001-07:00

CASE STUDY - Holmewood (NE Derbyshire)

With cheap imports the UK's coal industry has been in decline since the first half of the 20th century and in the 1990s many coal pits closed. This decline in the coal industry has had serious social and economic impacts on the mining communities which have relied on the coal industry for employment.

What was the problem in Holmewood?

- area grew up around the coal mine - community of miners houses
- closure of coal pit in 1970 - resulted in loss of 2299 jobs
- problem made worse as the rest of the coal industry in N Derbyshire continued to decline and in 1980s, a third of Holmewood's population was still reliant on coal mining for employment
- major unemployment problem (miners had very specialised skills and there were few other suitable jobs available).

Impact of the Closure:

1. Economic Impacts:

* 1987 - unemployment rate had reached 18% (much higher than national average of 10%)
* led to a spiral of decline (negative multiplier effect)
* with a low income, locals had less disposable income
* local businesses and shops experienced a loss of trade and many were forced to close

2. Social and Environmental Impacts:

* landscape littered with spoil heaps and derelict buildings associated with the coal industry
* poor quality housing (much lacking basic amenities) - locals, no money to spend on decorating / * regenerating houses (little disposable income due to unemployment)
* increase in crime and vandalism
* increased number of young leaving the area
* increase in stress-related illness.

Redeveloping the Area

A government Enterprise Zone (EZ) was set up in Holmewood in 1995 to regenerate the area by attracing new industry in. The government gave incentives such as cheap taxes and reduced rates resulting in the creation of an industrial estate and business park. The industrial estate was built at junction 29 of the M1. The redevelopment has been successful in creating new jobs, however employment levels in Holmewood remain below those for the rest of NE Derbyshire and many jobs were taken by those outside of Holmewood.

LINKS:

After coal – a future for Britain’s mining communities? - external link http://www.encyclopedia.com/doc/1G1-13688636.html

The Nuclear Debate

2008-04-29T03:21:00.001-07:00

Nuclear power is an increasingly important source of energy, accounting for over 20% of the UK's energy. Nuclear power uses heat obtained from uranium or plutonium atoms which are split. Water or gases (such as carbon dioxide) are used as a cooling system around the core. Steam is produced by heat created from the reactor and this steam is used to turn the turbines which in turn are used to generate electricity.

Nuclear Power in the UK
There are now about 20 nuclear power stations in the UK, including Sizewell (nr Dunwich - Suffolk Coast).

Where are nuclear power stations located and why?
Nuclear power stations tend to be located close to the coast because...

- they are remote and away from centers of population (due to the possible dangers which can be associated with nuclear power
- large quantities of water are required for the cooling process
- uranium is imported
- power stations need deep foundations

Nuclear power is still a controversial energy source and it is important that you are able to debate the fors and against of nuclear power.

What are the advantages of Nuclear power?

- only a small amount of uranium is required to produce very large amounts of energy
- nuclear power is a clean energy source - no toxic gases are released
- uranium is cheap and easily available
- it is a cheaper energy source than fossil fuels
- large reserves of uranium are available

What are the disadvantages of Nuclear power?

- problems associated with disposing of nuclear waste (remains a danger for a long time - thousands of years)
- although uranium is cheap, the power stations themselves are expensive to build in the first place (Sizewell - 1.5 billion pounds)
- whilst staff are highly trained there is potential danger - e.g. the Chernobyl disaster (Ukraine, 1986)
- it is expensive and difficult to make old power stations safe
- nuclear power stations are restricted in possible locations (must be on firm, stable land - usually away from large centres of population for safety).

Links:

The BBC Special Report – Nuclear Debate (excellent website with many reports / articles – up-to-date information) – External Link http://news.bbc.co.uk/1/hi/in_depth/sci_tech/2005/nuclear/default.stm
Nuclear Debate “Sizewell” – find out more about how the local community feel about having a nuclear power station in the area – External Link http://www.nucleardebate.co.uk/
Nuclear Power (Wikipedia) – External Link http://en.wikipedia.org/wiki/Nuclear_power
Nuclear Power – energy from splitting uranium atoms – External Link http://home.clara.net/darvill/altenerg/nuclear.htm
Analysis – Is nuclear power the answer? (BBC) – External Link http://news.bbc.co.uk/1/hi/sci/tech/4216302.stm
How Stuff Works – How Nuclear Power works – External Link http://www.howstuffworks.com/nuclear-power.htm
The Pros and Cons of Nuclear Power – External Link http://timeforchange.org/pros-and-cons-of-nuclear-power-and-sustainability

Case Study of a Distribution Industry - Argos Distribution Centre, Stafford

2008-04-29T03:01:00.001-07:00

What needs to be considered in the location of a distribution centre?

The operating costs and customer service will be very important in influencing the location of a new distribution centre and the new location must be considered in relation to its suppliers (transport networks) and promixity to its customers location (this will determine response time)

(photo credit: D Bagshaw - www.geograph.org.uk/photo/83754 -CCL)

Therefore things to consider will be:

Access to Motorways
Adequacy of surrounding infrastructure for the transport of goods in and out
Transport costs
Availability of workers and labour costs

CASE STUDY: ARGOS DISTRIBUTION CENTRE Acton Gate, Stafford (Staffordshire, E Midlands)

Argos, the pioneer of catalogue retailing is one of the UK's leading retailers with a total of 474 stores in the UK / Republic Ireland and with annual sales of over £3 billion, serving over 41 million customers per year.

As well as outlet shops based on their catalogue, there is Argos Direct, the home shopping service (based on both telephone and web based orders).

For a company like Argos, the location of its distribution warehouses is essential. Argos has a number of distribution centres, but its Home Delivery service (Argos Direct) has its national operations centre at the Acton Gate Distribution warehouse, Stafford which was opened in 1998.

The map opposite shows the location of the distribution centre. Why then did Argos choose to locate at this site?

- Easy access to the motorway and main access roads (J13 of the M6 crossed by the A449) for the transport of goods and access for workers
- The central location of the site in the Midlands means that drivers can have easy access to Argos's regional bases and drive through the night without exceeding their permitted number of work hours.
- Large, flat greenfield site (the warehouse itself is 600,000ft2), providing plenty of room for storage (essential for a distribution industry dealing with large volumes of stock), as well as transport and office facilities
- A plentiful labour supply from nearby Stafford.

There were however some problems with the location:
The site itself, although having excellent accessibility was not ideal for expansion opportunities due to be constrained by the surrounding transport networks (A440, M6 and railway - see map)

Since the opening of the Acton Gate centre a new centre has now opened at Milton Keynes (Marsh Leys) and a third and largest centre opened in Darlington in 2005, further helping to reduce delivery distances.

Exam Practice - a typical question based on this case study might be:
Name and locate an example of a distribution industry which you have studied in the UK. Explain why the distribution industry is located there. (6 marks)

Case Study - Manufacturing Industry - The Whitbread Brewery

2008-04-29T02:59:00.000-07:00

Traditionally all beer was brewed in local market towns on a small scale as it was bulky and expensive to move around. Today the trend is for large 'jumbo' breweries, but they are still market orientated (i.e. locate close to major markets).

(Photo credit at end of post)

What influences the choice of location for the brewing industry?

Raw materials required - malt; water; sugar; hops and yeast

The raw material needed in the largest quantity is water, but this is not significant to the location of the brewing industry as it is possible to source water either through the main system or by digging a borehole.
Hops and Malt are also easily available and for a reasonable price (transport costs are relatively low)
The costs of transporting the raw materials are therefore far less than the costs of transporting the beer to market
Therefore the brewing industry (market-orientated) tends to locate as close to the market as possible.

CASE STUDY: WHITBREAD BREWERY, Luton

Where was the original location of the brewery?

originally opened in London in 1796
in 1960s it needed a vast brewery to supply the large market area - the urban location of London meant that there was no room for expansion and transport costs to the rest of the South and East were expensive.

Where did the Brewery locate to and why?

A new "jumbo" brewery was built at Leagrave in Luton in 1976 - this site was chosen because:

it was the optimum least cost site for the market
very close to London and major towns (e.g. Watford, Stevenage
well placed for the SE England and W Midlands market
industrial land was available in the area
plenty of water was available from the boreholes in the Chiltern Hills
Raw materials could be transported easily by road - e.g. the M1 and M10
500 workers - skilled and local were available due to the closure of a small brewery at the time.

EXAM PRACTICE
An example of an exam question based on this case study:

Name and locate an example of a manufacturing industry or factory which you have studied in the UK. Explain why the manufacturing industry is located there. (6 marks)

Photo Credit: B Harris-Roxas http://www.flickr.com/photos/34546323@N00/103834807 - Creative Commons)

The Green Revolution

2008-04-29T02:54:00.000-07:00

In the 1960s, there was concern from the Indian government that the country would not be able to grow enough food to support the ever increasing population, so they put into place what was called the 'Green Revolution'. The idea of the 'Green Revolution' was to use technology to increase food output and as a result, over the last 50 years a series of changes have taken place in farming in India with the introduction of more 'Western-type' farming techniques.

What changes in farming in India did the Green Revolution bring about?

1. LAND REFORM -

The problem: Efficient farming was difficult in India due to the many small farms (75% less than 3ha), which had become a product of the 'Laws of Divided Inheritance' (with farms being split between the sons of the farmer on his death), many of the poor didn't even own land, whereas large amounts of land were owned by a few rich land owners

The GR (Green Revolution) solution: Land Reform - aimed to increase farm size, setting a limit on the amount of land the more wealthy could own and redistributing surplus land to those without.

2. HIGH YIELDING VARIETIES

The problem: existing rice varities, grew rapidly but very tall so fell over easily and had to be grown quite far apart.

The GR solution: money provided by MEDCs such as the UK, USA etc. enabled new high yielding varities of rice to be developed - resulting in the development of a new rice plant known as IR8. This was shorter and stronger; could be planted much closer together, enabling more crop per area; had a shorter growing season and produced almost 3-4 times as much yield per hectare.

3. MECHANISATION

The problem: rice growing is labour intensive, with many jobs to be done requiring great human input

The GR solution: technology such as tractors and mechanised ploughs were introduced from MEDCs, replacing water buffalo and increasing efficiency, reducing the required human input.

Other changes bought about by the Green Revolution:

(i) - Irrigation schemes, including the introduction of electric / diesel pumps to help ensure a more steady and reliable source of water for the new IR8 HYVs and large scale projects such as the Narmada River Project (a series of dams built to help provide water for irrigation of the land)

(ii) As the introduction of tractors and other 'Western' style technology was not as successful as first hoped, Alternative, 'Appropriate Technology' has been introduced which is suited to the local people's wealth, skills and knowledge, for example low cost irrigation schemes etc.

What were the successes of the Green Revolution?

(i) Those that could afford the new Hybrid seeds, technology etc. saw an increase of 300% in crop yields;

(ii) The overall increase in food production helped to feed the ever increasing poulation with India becoming largely self-sufficient

(iii) Increased output overall meant that some subsistence farmers had a surplus which they were also able to sell, helping to raise living standards further. Money raised in this was was also reinvested into the farm, helping with the costs of machinery etc. or to buy more land

(iv) Areas in which the Green Revolution was successful became richer and more money was available for investment in schools, clinics, industry etc.

What were the failures of the Green Revolution? (see also this excellent BBC Article for specific examples)

(i) Unfortunately for many farmers the cost of machinery was too much and they simply couldn't afford it, as well as the high initial outlay, money was also required for fuel and repair.

(ii) Many very poor farmers, were tenant farmers, with little money to buy even the new seeds or fertiliser that was required.

(iii) New irrigation schemes were required to provide the reliable source of water required by the HYVs (High Yielding Varieties of rice). As well as being expensive, in some cases where inappropriate schemes were used salinisation became a problem. Dam construction in some areas also resulted in the flooding of some good farming land.

(iv) The large amounts of fertilisers and pesticides required by the HYVs also led to serious environmental problems as they entered water supplies

(v) In areas where there was an increase in mechanisation, there was an increase in unemployment with fewer people needed to do the jobs that were now done using tractors etc.

(vi) The consequent increase in unemployment in rural areas led to an increase in rural-urban migration with more people moving to the cities, causing urban problems

(vii) Many farmers who had tried to take on the new technologies became heavily in debt, leading to increase stress and in some instances suicide.

Key Terms:

Green Revolution - the introduction of changes in farming in India since the 1960s, using new technologies to increase farming output

HYVs - New 'High Yielding Varities' of rice designed to increase output

Appropriate Technology - that which is economically and environmentally sustainable meeting the needs of the people in relation to their wealth, skills and knowledge

Links
Green Revolution (Wikipedia) - External Link http://en.wikipedia.org/wiki/Green_Revolution
India’s Green Revolution - External Link http://www.indiaonestop.com/Greenrevolution.htm
The limits of a Green Revolution (BBC Article) - External Link http://news.bbc.co.uk/1/hi/in_depth/6496585.stm
India – The Green Revolution - External Link http://countrystudies.us/india/104.htm
Green Revolution in India: A Case Study -External Link http://teacherweb.ftl.pinecrest.edu/SNYDERD/APHG/Unit%205/GreenRev.htm

Photo Credit: Jonathan Talbot, World Resources Institute. 2004. (http://www.flickr.com/photos/wricontest/466492667/)

Case Study of Subsistence Farming - Rice Farming in India

2008-04-29T02:50:00.000-07:00

Why Rice Farming in India?

1. CLIMATE - the Monsoon climate stays above 21oC with a long wet season, plenty of moisture available for growth, followed by dry, sunny weather which is ideal for ripening and the harvest

2. HUGE DEMAND - Rice is the staple food of 65% of the population of India and forms 90% of the total diet. India is indeed the world's second largest rice producer, producing 20% of the world's total)

3. FLAT LAND - ideal for paddy fields as it stops water draining away, allowing rice to grow in it

4. FERTILE SOILS - increases productivity and good crops are grown

5. WATER SUPPLY - plentiful water usually available due to the monsoon climate

6. LARGE LABOUR FORCE - rice farming is labour intensive and provides direct employment to about 70% of the working people in India where large numbers of workers are available.

What are the characteristics of the rice farms in India?

- many farms are very small (may only be one hectare - size of a football pitch)

- consequently rice farming is intensive, with large amounts of inputs compared to the size of the actual farm

- due to the small farm size and the poverty, often there is little no mechanisation and the farms are labour intensive (e.g. preparation of fields, planting, weeding etc.)

- the farmers are subsistence farmers - although they may sell what little surplus they might have and many poor farmers are only tenants as opposed to land owners.

Changes to the Rice Farming System:

- Natural disasters may severely affect farms - e.g. Typhoon Damage in October 1998 damaged yields
- Use of hybrid rice requires fertilisers and pesticides – expensive and can lead to health problems
- the characteristics of rice farms have also changed dramatically due to the Green Revolution

Photo Credit: treesftf http://www.flickr.com/photos/plant-trees/2805586701/

Changes in Farming in the UK

2008-04-29T02:44:00.001-07:00

After World War II the government launched a campaign to increase agricultural production to try and solve the problems of food shortages and eliminate the need for rationing that had occured during the war. The aim was quite simply to make the UK self-sufficient. As part of the government drive to increase farm production and efficiency, in 1973 the UK joined the Common Market (now known as the European Union) and adopted what was known as the Common Agricultural Policy.

The aims of the Common Agricultural Policy:

1. Stabilise markets, creating a single market in which the free movement of agricultural products could take place
2. Increase self-sufficiency by restricting imports and giving preference to produce from the European Union.
3. increase average field and farm size as well as to increase profit for farmers
4. Increase agricultural production by guaranteed prices for farmers

3 main policies were used to achieve the aims above, these were:

1. Subsidies and Grants - money was given to support farmers by supplmenting their income, in the form of subsidies. Grants were also given to enable farmers to fund schemes to increase production
2. Tarrifs (Import Taxes) - import taxes were used to restrict imports and therefore stimulate the market for products from the EU, further encouraging increased production.
3. Guaranteed Prices - regardless of world market prices, CAP ensured that farmers were guaranteed a fixed price for what they produced

By the mid-1980s, the Common Agricultural Policy had been so successful that over-production had become a problem with large surpluses of produce resulting in 'grain mountains'. A number of changes were made to CAP to try and control the problem of over-production, these included:

1. QUOTAS - these involved setting amounts for how much milk or crops could be produced. If farms exceeded these amounts then they were fined.
2. SET-ASIDE - the European Union funded set-aside in order to reduce the problems of surplus. This is where farmers were paid not to farm some of their land which would for example be left fallow or used for non-agricultural purposes. In 1995, due to the EU shortage of vegetable oil, farmers were paid a high subsidy of £445 per hectare for planting oilseed rape.
3. DIVERSIFICATION - farmers were encouraged to move into other areas of business to make money, this included PYO (Pick Your Own), Farm Shops, Bed and Breakfast, Renting out land etc.

Overall in response to the Common Agricutural Policy and the drive to increase agricultural production since World War II, there have been a number of key changes in arable farming in East Anglia over the last 50 years:

Key changes in Farming in East Anglia since 1950:

1. AGRIBUSINESS - farming has become large scale and 'capital intensive', now often run by large companies as opposed to being owned by individual farmers. These agribusiness companies use hi-technology and agrochemicals to maximise yields and maximise profits

2. FIELD SIZE & MECHANISATION - hedgerows have been removed to increase field size to increase production and also to enable machinery such as tractors, combine harvesters etc. to be used more efficiently.

3. LAND RECLAMATION - land, previously not used for agricultural production has been reclaimed in order to provide more opportunities for agricultural land-use. This has involved clearing woodlands, draining marshlands and fertilising sandy soils.

4. IMPROVED BUILDINGS - specialised buildings are now constructed, including temperature controlled storage sheds for drying grain and keeping harvested crops at optimum temperatures

5. CHEMICALS - there has been an increasing use of fertilisers to support new hybrid seeds and to increase yields, by allowing crops to continually be grown in the same fields without the need for crop rotation. There has also been an increase in the use of pesticides and herbicides.

6. DIVERSIFICATION - increasingly farmland is being used for other purposes such as camping, Bed and Breakfast facilities etc.

Environmental Issues resulting from changes in farming:

As a result of the changes above, there has been an increasing environmental impact, including:

(i) - almost 50% of the UKs hedgerows were removed between 1945-1990 resulting in the removal of important habitats, resulting in a decline in farm bird populations such as the skylark and corn bunting. Removal of the hedgerows has also resulted in increased soil erosion as there are no longer hedgerows to act as windbreaks.

(ii) the increase in use of pesticides and herbicides has increased water pollution as they are washed from the fields in runoff and leaching. This has led to eutrophication of surrounding water courses - i.e. the over-enrichment of the water with nutrients which has led to an overall decrease in species diversity as weed and other vegetation has proliferated at the expense of other water life.

Links:
Common Agricultural Policy (CAP) - Wikipedia - External Link
Q&A Common Agricultural Policy - BBC - External Link
Hedgerow Removal - Wikipedia - External Link

Photo Credit: ajgendorf25 http://www.flickr.com/photos/ajagendorf25/3181471308/

Case Study of Commercial Farming - Cereal Farming in East Anglia

2008-04-29T02:43:00.000-07:00

COMMERCIAL FARMING IN EAST ANGLIA - Lynford Hall Farm (Ely, Cambridgeshire)

Why is the area around Lynford Hall Farm ideal for arable farming?

CLIMATE - average annaul rainfall is approx 650mm , summers are warm around 26oC, ideal for ripening, cold winters break up the soil and kill off bacteria.
LAND - the land is very flat in this area, ideal for machinery
SOILS - well drained and fertile boulder clay - this area of the UK is often known as the 'bread basket of the UK' with its rich soils which are glacial in origin
MARKET - the area is close to a densely populated region (just North of London), with a large market for selling crops, supplying many major supermarkets of the East and South East.
COMMUNICATIONS - there are major road links, including the A1 and M11 which enable the rapid transport of crops to market.

What are the characteristics of the farm?

- crops grown include wheat, potatoes and peas
- it is a large farm with 570 hectares in area (it is an example of extensive farming - with relatively few inputs compared to size of farm)
- high output per hectare
- highly mechanised - uses large and specialist machinery and specialist buildings (e.g. grain store, with drying faciltiy and environmental cold stores for potatoes), there are a small number of full time workers

- uses good quality, hybrid seeds which are used to maximise the yields produced
- there is a heavy use of fertilisers and pesticides
- the output is cash crops which are produced and sold for profit
- profits are invested back into the farm - the farm is run by the family partnership, Sears Bros Ltd.

Changes to the System (for more info follow this link):

- a reduced labour force
- forced to streamline operations to save money
- have become increasingly computerised

Diversification:

- There are a number of bungalows on the land some of which have been sold, others are rented
- The farm has looked at the option of wind energy and the possibility of situation wind turbines on the land - however this has been met with objections and has not been undertaken

FOR FURTHER INFORMATION ABOUT LYNFORD HALL FARM INCLUDING SPECIFIC DETAIL ON THE FARMING SYSTEM, CHANGES etc. SEE THE FACE (Farming and Countryside Education) CASE STUDY PAGE

Photo Credit: Sarahpetherbridge http://www.flickr.com/photos/25890036@N07/3150728496/

Farming - An Introduction: The Farming System

2008-04-29T02:41:00.000-07:00

An Introduction to Farming

Types of Farming:

Knowing your key terms is important, make sure you learn the following:

1. Commerical Farming - the growing of crops / rearing of aniamls to make a profit

2. Subsistence Farming - where there is just sufficient food producted to provide for the farmer's own family

3. Arable Farming - involves the growing of crops

4. Pastoral Farming - invovles the rearing of animals

5. Intensive Farming - where the farm size is small in comparison with the large amount of labour, and inputs of capital, fertilisers etc. which are required.

6. Extensive Farming - where the size of a farm is very large in comparison to the inputs of money, labour etc.. needed

FARMING SYSTEMS

A farm is a system in that it has INPUTS, PROCESSES and OUTPUTS

INPUTS - these are things that go into the farm and may be split into Physical Inputs (e.g. amount of rain, soil) and Human Inputs (e.g. labour, money etc.)
PROCESSES - these are things which take place on the farm in order to convert the inputs to outputs (e.g. sowing, weeding, harvesting etc.)
OUTPUTS - these are the products from the farm (i.e. wheat, barley, cattle)

Depending on the type of farming e.g. arable/ pastoral, commerical / subsisitence, the type and amount of inputs, processes and outputs will vary.

You need to make sure you are able to define and give examples of Inputs, Processes and Outputs in farming systems. You also need to be able to give the characteristics of two different types of farming system. Consequently, there are two Farming case studies you will need to learn:

1. Case Study of Commercial Farming in an MEDC - Arable Farming in E Anglia (Lynford Hall Farm - Cambridgeshire)

2. Case Study of Subsistence Farming in an LEDC - Rice Farming in India.

Distribution of Farming in the UK

The type of farming dominant in a particular area will depend on the climate, relief and soil type of an area. Within the UK different farming types are dominant in different areas (see the diagram below)

Links
Farming as a System (BBC Bitesize) - external link

Photo Credit - Paul Keleher http://www.flickr.com/photos/pkeleher/2746648333/

Case Study of Rapid Economic Growth - South Korea (An NIC)

2008-04-29T02:39:00.000-07:00

SOUTH KOREA - AN NIC

South Korea, lacks natural resources, however it has a plentiful, cheap and flexible workforce, this has led to it becoming an NIC (Newly Industrialised Country), with rapid industrialisation occuring over the last 50 years. You need to know what the CAUSES and CONSEQUENCES of this rapid industrial growth have been.

What were the CAUSES of South Korea's rapid economic growth?

- the government realised that agricultural production was not the route to economic growth and as a result encouraged foreign investment e.g. from the USA and themselves invested in large companies such as the state-owned Steel Works (Pohang Iron and Steel corporation)

- South Korean firms (such as Hyundai, Samsung and Daewoo) were also producted by high import taxes - this ensured that there was a sufficient market for goods, further stimulating production.

- the government also developed its own research and development of hi-tech goods

- large TNCs (e.g. Sony from Japan) were attracted by low wages, low taxes and they also bought know-how to South Korea

- a dedicated and substantial workforce was available, willing to work long hours

- firms were also attracted by a large consumer market of SE Asia (e.g. China)

What have the CONSEQUENCES of South Korea's rapid economic growth been?

ADVANTAGES OF RAPID INDUSTRIAL GROWTH:

(i) South Korea became very successful competing with MEDCs such as the UK

(ii) More jobs were available, helping to reduce unemployment and with the rise in income, there was more money available in the country for buying consumer goods and helping to increase standards of living

(iii) The increase in purchase of consumer goods (e.g. cars / electrical goods), created more demand for the goods and therefore led to a further increase in the market

(iv) More money was also available for leisure time (greater disposable income), resulting in a growth in the countries service sector

(v) More money was invested in the infrastructure, improving road networks and airports

(vi) The success of industrialisation and the development of South Korea's industries, led to South Korean TNCs (e.g. Samsung) investing in places such as the USA

(vii) South Korea became the leading producer of shipbuilding (due to low labour costs / modern ship building yards)

(viii) The South Korean car industry flourished, with companies such as Hyndai and Kia linking with industries in the USA / Japan and the companies have also invested in LEDC countries.

DISADVANTAGES OF RAPID INDUSTRIAL GROWTH:

SOCIAL PROBLEMS

- unequal pay (women and immigrants paid only 50-75% the wages paid to men), sweat shop working conditions for some and an increase in child labour

- working very long hours (an average of 52 hours a week)

- increased rural-urban migration (the most innovative began moving away from the countryside into the nearby cities for work)

ENVIRONMENTAL PROBLEMS

- noise, air and water pollution increased due to the rapid industrialisation

- the increase in factories led to smog over cities

- increased traffic volumes led to taxes on road use in the capital, Seoul

- in some areas which experienced an increase in population, services such as sewage treatment were not able to cope

- rapid growth resulted in some instances in poor workmanship and there were instances of deaths from collapsing buildings (e.g. the Sampoong Department Store in 1995 (507 deaths))

ECONOMIC PROBLEMS

- when there was a downturn in World Trade in 1997, many S Korean banks faced huge debts / bankruptcy

Links:
- Economy of South Korea - External Link: http://en.wikipedia.org/wiki/Economy_of_South_Korea

Photo Credit: SOM http://www.flickr.com/photos/architectural-design/3058602909/

Practice Paper - Unit 4 - People and their Environment - OCR A

2008-04-29T01:07:00.000-07:00

Here is the fourth and final set of Practice Past Paper activities - with a total of 10 questions drawn from past papers relating to Unit 4 of the OCR A Course - People and their Environment. The questions are based on the Quarrying and Mining, Tropical Rainforests, National Parks, Water Pollution, Acid Rain and Global Warming Topics. Remember - the suggested answers are just that - there are many ways the answer could be written - but the suggested answers show you the level of detail required and the sorts of points you need to include.

Click below to begin

REMEMBER - Level 3 answers require place specific detail so learn your case studies well

Practice Paper - Unit 3 - People and their Needs - OCR A

2008-04-29T01:03:00.000-07:00

Here is the third of the Practice Past Paper activities - with a total of 13 questions drawn from past papers relating to Unit 3 of the OCR A Course - People and their Needs. The questions are based on the Quality of Life, Economic Activities and Energy Topics. Remember - the suggested answers are just that - there are many ways the answer could be written - but the suggested answers show you the level of detail required and the sorts of points you need to include.

Click below to begin

REMEMBER - Level 3 answers require place specific detail so learn your case studies well!

Practice Paper - Unit 2 People and Places to Live - OCR A

2008-04-29T00:59:00.001-07:00

Here is the second of the Practice Past Paper activities - with a total of 11 questions drawn from past papers relating to Unit 2 of the OCR A Course - People and Places to Live. The questions are based on the Population and Settlement Topics. Remember - the suggested answers are just that - there are many ways the answer could be written - but the suggested answers show you the level of detail required and the sorts of points you need to include.

Click below to begin

REMEMBER - Level 3 answers require place specific detail so learn your case studies well!

Practice Paper - Unit 1 People and the Physical World - OCR A

2008-04-27T06:27:00.000-07:00

As you enter the last few weeks of revision in the run up to the final exams you should be practicing answering past questions as well as learning the content you have been taught. Over the next couple of days, four interactive practice papers will appear here, one for each of the four units in the OCR A Geography GCSE course. Each paper has a number of past questions (with a focus on the 4 -6 mark questions) drawn from the appropriate unit from a selection of past papers. You can select a random question or tackle all those available. Once you have typed your answer you can print it and a sample answer will appear for you to check to see whether you have covered the key points.

Click below to begin

REMEMBER - Level 3 answers require place specific detail so learn your case studies well!

Coasts Revision

2007-08-20T12:39:00.000-07:00

Revising the Coasts Unit:
We have now come to the end of the Coasts Unit and its time to revise!
Here are some resources to help you.

Check list of key concepts to revise:

1. Energy at the coast - types of waves and basic principles behind wave formation / factors affecting the strength of waves

2. Coastal Processes - erosion processes (you need to be able to describe the processes and how they work); transport processes (you must be able to talk through the process of longshore drift and it helps if you are able to draw an annotated diagram to show the process) and deposition

3. Coastal Erosion Landforms - you must be able to talk through both the features and formation of the following landforms: cliffs; wave-cut platforms; headlands and bays; caves, arches, stacks and stumps (in your description and explanation of formation always include some examples of named erosion processes that may be at work). You should also be able to draw annotated diagrams of the features to show how they form as well as knowing named examples of each.

4. Coastal Deposition Landforms - you must be able to talk through both the features and formation of the following landforms: beaches; spits; bars and tombolos. You should be able to draw annotated diagrams of the features to show how they form as well as knowing named examples of each.

5. Case Study of Coastal Erosion - learn (including detail - i.e. location, facts and figures) a case study of coastal erosion - either Dunwich or the Holderness Coast.

6. Coastal Defence - you need to be aware of the options for coastal defence - hard engineering, soft engineering or managed retreat. You should be able to describe coastal management techniques and be able to discuss their advantages and disadvantages. You should learn a named case study to back this up - for example either Aldeburgh or Overstrand.

Revision Resources:
- make good use of your class notes
- make use of blog posts to consolidate your understanding / recap concepts you are less sure of (to access previous posts - use blog archive list on the left hand side of the blog - August posts) - remember there are various links to animations etc. to help you.

Interactive Revision Quizzes:
You must learn your notes (particularly case study detail) but once you have revised from your notes there are some interactive revision quizzes etc. here for you to test yourself.
Coast Key Word Flash Cards (definitions then key words)
Coasts Key Word Flash Cards (key words then definitions)
Coasts Key Word Test
Coastal Features Recognition and Examples Test
Coastal Management Quiz
Coasts Revision Quiz 1
Coasts Revision Quiz 2 - Penalty Shootout
Coasts Revision (Walk the Plank) - Hull Trinity School
Coasts Questions - Practice Paper
Coasts Downloadable Flashcards
Coasts Revision Dominoes
Coastal Features Countdown Conundrum
Crazy Coasts (Half a min - anagrams)
Coasts Dustbin Game - sorting erosion and deposition features
Coasts Dustbin Game - Erosion and Deposition Features Case Studies

Coasts Podcasts
Podcast 1 - Energy at the Coast - waves and wave formation
Podcast 2 - Coastal Processes
Podcast 3 - Coastal Erosion Features
Podcast 4 - Coastal Deposition Features
Podcast 5 - A case study of coastal erosion - Dunwich
Podcast 6 - Coastal Defence

Coastal Defence

2007-08-20T07:10:00.000-07:00

When managing the coastline there are two main options:
1. HARD ENGINEERING
- this is where man made coastal defence structures are used to reflect large amounts of wave energy and hence protect the coastline.
2. SOFT ENGINEERING
- this is where beaches or naturally formed materials are used to control / re-direct erosion processes.

You need to know examples of coastal management techniques and their advantages and disadvantages:

Hard Engineering Techniques:

1. Re-Curved Sea Wall
- concrete wall which is curved on the underside to deflect the power of the waves
- these can be very expensive (up to £1-2 million per km) and the deflected waves can scour material at the base of the wall causing them to become undermined
- these are however a very effective means of preventing erosion and they reflect rather than absorb wave energy.

2. Rip Rap
- large boulders on the beach absorb wave energy and break the power of the waves
- although movement of the boulders is expensive this can be a much cheaper method than some other solutions
- the boulders can however be undermined easily by waves washing away sand and shingle beneath them. They also can be quite ugly, changing the appearance of a coastline.

3. Groynes
- these structures (usually either wooden or steel) are designed to top longshore drift and therefore act to build up and anchor beach material, protecting the base of cliffs.
- they are effective at reducing erosion in the area they are constructed in by causing significant build up of beach material
- groynes may however starve areas further down the coast of material by stopping longshore drift, resulting in an increase in erosion in these areas

4. Gabions
- these cages of boulders are built into cliff faces to protect the cliff from the force of the waves;
- they are cheaper than sea walls and can be very effective where severe erosion is a problem
- they are however visually intrusive

5. Revetments - these wooden structures break the force of waves and beach material builds up behind them
- they are cheap and effective at breaking waves
- as well as being visually intrusive however they do need replacing more frequently than most other defence methods.

Soft Engineering Techniques

Soft engineering includes beach replenishment in which beach material is added to provide a "natural solution". Environmentally this is a preferred option as it maintains the beauty of the landscape and avoids visual intrusion, however it can be expensive to maintain as longshore drift continues to move beach material down the coast and therefore regular replenishment is required.

Sand Dunes and salt marshes can also be encouraged to act as natural barriers to the waves.

Case Study of Coastal Defence: Aldeburgh (Suffolk)

Aldeburgh is just south of Dunwich, here a large scale coastal defence scheme is in place to control erosion. Aldeburgh is a busy town and tourism is very important to the local economy in this area. It is therefore seen as cost effective to have a coastal defence scheme in place to protect the economically valuable land.

Hard engineering is in place with a combination of sea wall, rip rap and groynes. There is also an area of salt marsh to absorb some of the waves energy should it breach the sea wall.

Another area severely affected by coastal erosion and where significant coastal defences are in place is Overstrand on the North Norfolk Coast, pictures of the coastal defences in this location can be seen here.

Further north, the small village of Dunwich is also severely affected by coastal erosion, yet very little, apart from some small soft defences and a recent limited and unsuccessful attempt at hard engineering is in place - here is a very useful account of the reasons for the differences in the extent of coastal defence between Dunwich and Aldeburgh.

Wooden Revetments and Gabions:

Follow up links:
Download a Coastal Defences summary sheet (includes advantages and disadvantages)
Coastal Management (BBC Bitesize)
Coastal Management Strategies (S-Cool) - very good!

Podcast: Coastal Defences
You can listen to a podcast of this post below - to download a copy to listen to on your .mp3 player click here.

Case Study of Coastal Erosion - Dunwich (Suffolk)

2007-08-20T06:45:00.000-07:00

The Suffolk coastline of East Anglia has been eroding for 1000s of years and suffers rapid and frequent change - the changes are due to the coastal processes of erosion and deposition and the large scale movement of material down the coast by longshore drift.

Dunwich is a very small village located on the east coast in Suffolk. Dunwich was once a thriving port, similar in size to London, but storms, erosion and floods have almost wiped out this once prosperous settlement, which once had a population of 4,000 as well as a flourishing port. All that remains now are a few cottages - yet at one time there were 6 churches and 3 chapels. Most of old Dunwich now lies on the sea floor.

It is predicted that with our changing climate, storm events will become more frequent and in 1990, 7 metres of the coastline was lost over a few days in a storm that hit the Dunwich Coast.

So why is Dunwich so affected by coastal erosion?
- the coastline at Dunwich is made up of soft rock (sands, gravels and clays), these are easily eroded by the sea;
- the problem is made worse by the narrow beach which results in wave attack at the base of the cliff;
- the cliff faces are also greatly affected by weathering processes;

Rates of erosion at Dunwich are now as great as one metre per year. Material that is eroded from the Dunwich cliff line is moved down the coast by the process of longshore drift, keeping the beach fairly narrow. The material is transported in a N-S movement where it is deposited further south to form Orfed Ness Spit.

Although prone to severe coastal erosion, Dunwich has relatively little sea defence. An area of marshland just beyond the car park has been protected from the sea by a long shingle sea wall, but this has to be regularly rebuilt by bulldozers. Until recently there has been no other coastal management and the natural creation of a new beach to absorb wave energy has been seen as the most effective solution, due to the small size of Dunwich it has not be seen as cost effective to spend millions on sea defence at this location. However in February 2007, a new experimental beach stabilisation project began, it has been designed to try and reduce the severe cliff failures. A series of sand and shingle humps are to be created to stop the beach eroding and therefore help to reduce cliff erosion.

Another good example of coastal erosion is the Holderness Coast (Humberside)

Follow up links:
The Geology of Dunwich
Dunwich Photographs (Thanks to A Stacey "The Geography Department")
Low tide reveals lost city (BBC Article)
Work to shore up Beach to start (BBC Article)
Disappearing Village - sea claims another piece of Dunwich (Guardian Article from 1999)

Podcast: Case Study of Coastal Erosion - Dunwich
You can listen to a podcast of this post below - to download a copy to listen to on your .mp3 player click here.

Coastal Deposition Landforms: Features and Formation

2007-08-20T06:27:00.000-07:00

Material that is transported by the waves along a coastline is eventually deposited forming distinctive deposition features. There are four main deposition features that you need to learn the formation of. These are:

1. Beaches
2. Spits
3. Bars
4. Tombolos

Beaches Beaches are the main feature of deposition found at the coast, these consist of all the material (sand, shingle etc.) that has built up between the high and low tide mark. There are number of different sources of beach material - the main source being rivers, where fine muds and gravels are deposited at the river mouth. Other sources of beach material include longshore drift (bringing material from elsewhere along the coast); constructive waves (bringing material up the beach from the sea) and from cliff erosion.

As constructive waves build up beaches, they often form ridges in the beach known as berms. The berm highest up the beach represents the extent to which the water has reached during high tide.

Click on the diagram below to see the main sources of beach material

SPITS
Spits are long narrow ridges of sand and shingle which project from the coastline into the sea.

The formation of a spit begins due to a change in the direction of a coastline - the main source of material building up a spit is from longshore drift which brings material from further down the coast.

Where there is a break in the coastline and a slight drop in energy, longshore drift will deposit material at a faster rate than it can be removed and gradually a ridge is built up, projecting outwards into the sea - this continues to grow by the process of longshore drift and the deposition of material.

A change in prevailing wind direction often causes the end of spits to become hooked (also known as a recurved lateral).
On the spit itself, sand dunes often form and vegetation colonises (for example Blakeney Point - North Norfolk)
Water is trapped behind the spit, creating a low energy zone, as the water begins to stagnate, mud and marshland begins to develop behind the spit;
Spits may continue to grow until deposition can no longer occur, for example due to increased depth, or the spit begins to cross the mouth of a river and the water removes the material faster than it can deposited - preventing further build up.

Examples of Spits
- Spurn Head - Holderness Coast
- Orford Ness - Suffolk

Click below for an annotated diagram of spit formation:

BARS

These form in the same way as a spit initially but bars are created where a spit grows across a bay, joining two headlands. Behind the bar, a lagoon is created, where water has been trapped and the lagoon may gradually be infilled as a salt marsh develops due to it being a low energy zone, which encourages deposition.

Example of a Bar: Slapton Sands - Devon.

TOMBOLOS

Tombolos are formed where a spit continues to grow outwards joining land to an offshore island.

Example of a Tombolo: - Chesil Beach - which joins the South Dorset coast to the Isle of Portland.

-------------------------------------------------------------------------------
REVISING COASTAL DEPOSITION FEATURES

Remember - as well as being able to describe the formation of each feature of coastal deposition, you should be able to give a named and located example e.g. a spit - Spurn Head (Holderness Coast). You should also try and learn a labelled diagram to show the formation of each feature.

- Beach - Dawlish Warren (Devon)
- Spit - Orford Ness (Suffolk) or Spurn Head (Holderness Coast)
- Bar - Slapton Sands (Devon)
- Tombolo - Chesil Beach (joining S Dorset Coast to Isle of Portland)

Having now learnt both erosion and deposition features you need to make sure that you can distinguish between them. Have a go at the dustbin game below - click on play to begin. Start by studying the two lists when you think you are ready to test yourself on whether a landform is a feature of erosion or deposition start the game by clicking proceed. Drag the feature to the correct dustbin to make your choice!

click here for full screen version

Follow Up Links:

Animation of spit formation (Wycombe High School Link)
Bar and Spit Animation (Wycombe High School Link)
Longshore Drift Animation
Simple Longshore Drift Animation

Key Terms Check
Spit - a ridge of sand and shingle projecting from the mainland into the sea
Bar - a ridge of sand and shingle which has joined two headlands, cutting off a bay
Tombolo - a ridge of sand and shingle joining the mainland to an island

Podcast: Coastal Deposition Features
You can listen to a podcast of this post below - to download a copy to listen to on your .mp3 player click here.

Coastal Erosion Landforms - Features and Formation

2007-08-20T05:35:00.000-07:00

Coastal Erosion Features

There are 3 main groups of coastal features which result from coastal erosion:
1. Headlands and Bays
2. Caves, Arches, Stacks and Sumps
3. Cliffs and Wave-cut platforms

Before you revise the formation of these landforms, have a look at this video and make sure you are able to identify the landforms from their distinctive features.

Click To Play

1. HEADLANDS AND BAYS

Headlands are resistant outcrops of rock sticking out into the sea, whilst bays are indents in the coastline between two headlands.

So how do headlands form?

- Headlands form along discordant coastlines in which bands of soft and hard rock outcrop at right angles to the coastline.
- Due to the presence of soft and hard rock, differential erosion occurs, with the soft, less resistant rock (e.g. shale), eroding quicker than the hard, resistant rock (e.g. chalk)
- Where the erosion of the soft rock is rapid, bays are formed
- Where there is more resistant rock, erosion is slower and the hard rock is left sticking out into the sea as a headland.
- The exposed headland now becomes vulnerable to the force of destructive waves but shelters the adjacent bays from further erosion.

Named Examples of Headlands and Bays: (LEARN!)

The Dorset coast has excellent examples of Headlands and Bays
e.g. Swanage Bay and the Foreland (a headland)

2. CAVES, ARCHES, STACKS and STUMPS

Once a headland has formed it is then exposed to the full force of destructive waves and it gradually begins to erode. you need to be able to describe the erosion of a headland and the features that form.

For the sequence of formation see the animation below:

Click To Play

So how does a headland erode and caves, arches, stacks and stumps form?

- Firstly, the sea attacks the foot of the cliff and begins to erode areas of weakness such as joints and cracks, through processes of erosion such as hydraulic action, wave pounding, abrasion and solution;
- Gradually these cracks get larger, developing into small caves;
- Further erosion widens the cave and where the fault lines runs through the headland, two caves will eventually erode into the back of each other forming an arch, passing right through the headland.
- A combination of wave attack at the base of the arch, and weathering of the roof of the arch (by frost, wind and rain), weakens the structure until eventually the roof of the arch collapses inwards leaving a stack, a stack is a column of rock which stands separate from the rest of the headland.
- The stack will continue to erode, eventually collapsing to form a stump which will be covered by water at high tide.

Named Examples:

The Foreland (Dorset Coastline) is a great example of a headland which shows these features - there is a distinctive stack called Old Harry and a stump known as Old Harry's Wife.

A good example of a distinctive arch, also found on the Dorset Coast is Durdle Door.

3. CLIFFS AND WAVE-CUT PLATFORMS

Cliffs are steep rock faces along the coastline, they tend form along concordant coastlines with resistant rocks parallel to the coast.

So how do cliffs and wave-cut platforms form?

- The erosion of a cliff is greatest at its base where large waves break - here hydraulic action, scouring and wave pounding actively undercut the foot of the cliff forming an indent called a wave-cut notch whilst the cliff face is also affected by abrasion as rock fragments are hurled against the cliff by the breaking waves.
- This undercutting continues and eventually the overhanging cliff collapses downwards - this process continues and the cliff gradually retreats and becomes steeper.
- As the cliff retreats, a gently-sloping rocky platform is left at the base, this is known as a wave-cut platform which is exposed at low tide.

Named Examples:

Good examples of cliffs and wave-cut platforms can be found at Hunstanton (North Norfolk) and Flamborough Head (Yorkshire)

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REVISING COASTAL EROSION FEATURES

Remember - for each erosion feature try and learn a labelled diagram to show its formation, make sure that you also mention examples of erosion processes when describing how the features are actually formed. Finally to access the highest marks remember to name and locate examples of each feature.

- Swanage Bay (Dorset Coast)
- The Foreland (Headland) (Dorset Coast)
- Old Harry (Stack) (Dorset Coast - off of the Foreland)
- Old Harry's Wife (Stump) (Dorset Coast - off of the Foreland)
- Durdle Door (South Dorset Coast)
- Cliffs and Wave-cut platforms - Hunstanton (N Norfolk) and Flamborough Head (Yorkshire)

Click here for examples of 6 mark answers on the formation of coastal erosion features

Follow up Links:
Erosion of a Headland
Animations of Cliff formation
Cliff Features and Arch Animation

Podcast: Coastal Defences
You can listen to a podcast of this post below - to download a copy to listen to on your .mp3 player click here.

Coastal Processes: Erosion, Transport and Deposition

2007-08-20T05:07:00.000-07:00

Remember, there are 3 main processes that cause a coastline to change:
1. Erosion
2. Transport
3. Deposition.

There are number of factors which affect each of these processes - we are going to start by exploring erosion processes and the factors that can affect the amount of erosion that may take place along a coastline.

COASTAL EROSION

Erosion Processes:
Erosion is the wearing away of rocks, at the coast there are 6 main types of erosion processes in action (see animations here):

1. ABRASION (this is also known as corrasion) - this is where rock fragments are hurled at cliffs by breaking waves, gradually scraping away at the cliff face;

2. HYDRAULIC ACTION - as waves break against the cliff face, the pressure of the breaking wave can compress air in cracks. This compressed air gradually forces open the crack in the rock - as this process continues, the rock becomes increasingly weakened.

3. SOLUTION (this is also known as corrosion) - this occurs where the salt water is able to dissolve some of the chemicals in rocks - for example, limestone cliffs are gradually weakened as the salt water dissolves the calcium carbonate in the limestone.

4. SCOURING - this occurs at the base of the cliff as the waves break and swirl around, gradually removing loose rock.

5. ATTRITION - this is where rock fragments carried by the waves hit against each other and gradually wear down to form sand and silt

6. WAVE POUNDING - the sheer force of waves hitting against the cliff face

These processes of erosion form a series of distinctive landforms at the coast.

Rates of Coastal Erosion

So what are the factors that determine how much erosion can take place at the coast?

1. The Resistance of the Rocks - e.g. limestone, chalk and granite are resistant rocks (often forming cliffs and headlands) and erode relatively slowly, whilst less resistant rocks such as clay are easily eroded.

2. The Strength of the waves - affected by the wind strength and duration and its fetch

3. The shape of the coastline (which is dependent on its geology) - on concordant coastlines, rocks are parallel to the wave front and therefore rates of erosion are similar along the coastline. On discordant coastlines, differential erosion may occur, where bands of hard and soft rock outcrop at right angles to the sea. Consequently headlands and bays form along discordant coastlines and whilst headlands remain exposed to the force of the waves, bays are sheltered.

Click on the diagram below for a summary of factors affecting coastal erosion

COASTAL TRANSPORT

The second process operating at the coast is transport. Material eroded by the sea is carried within the water in a number of ways, minerals dissolved from rocks are carried in solution, whilst small rock fragments, light enough to be held within the water, float in suspension. The largest rock fragments which are too heavy to be picked up by the waves, are transported by the process of traction, this is where they roll along the bed when the waves pick up enough energy. Finally, medium sized rock particles, which cannot be carried by the waves all the time, are moved by saltation. This is where during times of higher wave energy the particles are picked up and then dropped again as the wave looses its energy.

The main form of transport operating at the coast is that of LONGSHORE DRIFT.

Longshore drift is the process by which sand and pebbles are moved along a beach by the movement of the waves.

COASTAL DEPOSITION

Material is moved up the beach by the swash at an angle which is controlled by the prevailing wind. The backwash then carries material back down the beach at right angles to the coastline under the influence of gravity. Gradually the material is moved along the coastline, its direction being controlled by the prevailing wind direction.

The final process operating at the coast is that of deposition - this is where material that is too heavy to be transported any more is left behind, building up the beach. Due to the importance of energy in transporting sand and shingle, it is the largest material that is deposited first. A number of distinctive features may form due to coastal deposition.

Follow up links:
Animations of Coastal Erosion Processes (BBC Bitesize)
Transport and Deposition (BBC Bitesize)

Key Terms Check:
Erosion - the wearing away and removal of material
Deposition - the dropping of material
Abrasion - the wearing of rock due to rock fragments being hurled against cliffs
Attrition - the breakdown of rocks as they hit against each other
Hydraulic Action - the force of waves causing rocks to split apart as waves compress air in cracks in the rocks
Wave Pounding - sheer force of water hitting rocks
Solution - where minerals in rocks are dissolved by the action of sea water
Scouring - occurs where water and broken rock fragments swirl around at the base of cliffs gradually wearing rock away.
Longshore Drift - the movement of material along a coastline

Podcast: Coastal Processes
You can listen to a podcast of this post below - to download a copy to listen to on your .mp3 player click here.

Coasts - Energy at the Coast

2007-08-20T04:57:00.000-07:00

The coast represents the metting point between the land and sea. Coasts are very dynamic areas and they are constantly change. This change is due to 3 main processes which operate at the coast, 1. Erosion; 2. Transport and 3. Deposition. These 3 processes are all driven by the amount of energy that is available at the coast. The main agents of change at the coasts are waves. Waves are movements of energy throughout the water, but where do waves get their energy from? The answer to this is wind.

As wind blows over the surface of the sea, it creates friction. This frictional drag causes water particles to begin to rotate and energy is transferred forward in the form of a wave. Whilst the water moves forward, the water particles return to their original position. As a wave reaches shallow water, friction between the sea bed and the base of the wave causes the wave to begin to slow down and its shape becomes more eliptical. The top of the wave however, unaffected by the friction, becomes steeper until it eventually breaks. When the wave breaks, water washes up the beach, this is called the swash. The movement of water backdown the beach is called the backwash.

It is the rate at which waves reach the coast which determine whether the main process acting on the coastline is erosion or deposition. There are two main types of waves:

(i) CONSTRUCTIVE WAVES - tend to arrive at the coast at a rate of less than 8 waves per minute, they are low energy waves and are small in height. They have a strong swash and a weak backwash. This means that constructive waves tend to deposit material and build up a beach.

(ii) DESTRUCTIVE WAVES , have much higher energy and tend to arrive at the coast at a rate of more than 8 per minute. They are much larger in height often having been caused by strong winds and a large fetch. These high energy waves have a weak swash but a strong backwash, which erode the beach but pulling sand and shingle down the beach as water returns to the sea.

There are 3 main factors which will affect the strength of a wave and therefore whether it is more likely to erode or build up the coastline:
(i) the strength and speed of the wind - the faster the wind, the more energy is transferred and therefore the bigger the wave that is produced.
(ii) the duration of the wind - this is the length of time for which the wind has blown - the longer the wind blows, the more energy is transferred to the wave
(iii) the fetch - this is the distance over which the wind has blown and therefore how far the wave has travelled. The longer the fetch, the larger the wave is likely to be.

Follow up links:
Excellent Animation showing a wave forming and breaking (Wycombe High School)
Wave Machine Simulator - create your own ocean wave
Ocean Surface Wave - Wikipedia
Waves - includes animation of swash and backwash (BBC Bitesize)
Constructive and Destructive Waves Animation (Wycombe High School)

Key Term Check:
Swash - the movement of water and material up the beach (in direction of prevailing wind)
Backwash - the movement of water and material back down the beach (straight back down due to gravity
Constructive wave - low energy wave with greater swash than backwash - tends to build up the beach
Destructive wave - high energy wave with greater backwash than swash - tends to erode beach

Podcast: Energy at the Coast - Wave Formation
You can listen to a podcast of this post below - to download a copy to listen to on your .mp3 player click here.

The Interdependence of Settlements: Case Study - St Ives

2007-08-15T09:01:00.000-07:00

You need to be aware of the interdependence of settlements within a hierarchy, with reference to the sphere of influence of places and the types and order of services that they provide. The map below shows the local area around St Ives which includes surrounding towns, villages and hamlets. The sphere of influence of St Ives incorporates many smaller villages including Somersham, Needingworth, Bluntisham, Holywell, Fenstanton and Hemingford.

Image produced from the Ordnance Survey Get-a-map service. Image reproduced with kind permission of Ordnance Survey and Ordnance Survey of Northern Ireland.

Click on the image below to download a .pdf copy of the sheet showing the hierachy of settlements and services provided within which St Ives is part.

Settlement Hierarchies

2007-08-15T09:00:00.000-07:00

Settlements within an area vary greatly in physical size, population and the number of services that they provide. When studying settlements within an area we can look at them in terms of a settlement hierarchy. A settlement hierarchy is when settlements are put into an order based upon their size or the services that they provide for people (see hierarchy diagram below). As you go up the hierarchy there is an increase in the size of the settlement, population and number of services; the distance between these settlement types also increases. The number of settlements of each type however decreases as you move up the hierarchy.

Settlements in the hiearchy are interdependent as people will use a variety of services found in different settlements. The area served by a particular settlement is known as its sphere of influence. The size of this will be dependent not only on the type and number of services offered by a town but also the size of the town and the ease of access related to the available transport networks serving the area. Villages usually provide few services, and those that exist are mainly low order services or sell low order goods. Low order goods / services are those that are low in value / cost and are used / required daily, for example milk / newsagents. Larger towns and services will have a greater range of services, including both low order and high order goods and services. High order goods and services are more expensive in nature and not required so frequently. They are often comparison goods, such as furniture, electronic goods etc. and people are usually prepared to travel further in order to get them. The distance that people are prepared to travel to use a service or obtain a good is known as its range. Services such as hypermarkets and goods such as furniture have a much greater range than for example a newsagents and milk.

In order to be profitable, a shop or service will require a minimum number of potential customers, this is known as its threshold population. Shops/services providing low order goods or services usually need a much lower threshold population (as the goods / services are required / used daily), whilst high order shops / services will require a much greater number of potentail customers and thus have a higher threshold population. Marks and Spencers for example may require a threshold population of 70,000 before the store can be profitable.

The needs of local communities are often provided for by neighbourhood shopping centres. These consist of a group of low order shops and services, e.g. a newsagents, bakery, hairdressers etc. serving an area within a town, for example Kings Hedges, St Ives. Out-of-town shopping centres which usually contain higher order shops, including large chain and department stores have increased in number and size significantly over the last 20 years or so and in doing so have had a negative on some nearby town centres.

Follow up links:
Settlement Hierarchy (BBC Bitesize)
Settlement Hierarchy (Wikipedia)
Shopping Hierachies

Key terms check:
Settlement Hierarchy - where settlements are put into order based upon their size or services provided.
High Order Goods - usually high cost goods - bought now and again - e.g. furniture
Low Order Goods - usually low cost goods needed often - e.g. milk
Sphere of Influence - area served by a settlement
Neighbourhood Centre - a group of low order shops serving a community within a town
Range of a Good - maximum distance people are prepared to travel to obtain a service
Threshold - minimum number of people needed to ensure that demand is great enough for a service to be offered

Second Homes - Social and Economic Impacts

2007-08-15T08:59:00.000-07:00

Increasing disposable incomes have resulted in an increase in second home ownership. Many of these homes are used for weekends or holidays in attractive rural areas. The increase in second home ownership has however bought some ill feeling by locals who have felt the impact of changes in villages caused by second homes. An increase in second homes in an area can bring both benefits and problems.

Benefits:
- provides trade for local trades such as builders, plumbers etc.
- tourists
- existing home owners have seen an increase in the value of their homes
- older properties in need of repair have been restored
- tourists do bring in some money to the local area

Problems:
- house prices increase due to competition between buyers of second homes causing many youngsters to be outpriced from their own local area
- villages can become 'sleepy' as some houses remain empty for much of the year - this has also resulted in the closure of some local shops and services due to a fall in demand
- a reduction in public transport services
- some gentrification / improvements carried out by second home owners are not in keeping
- reduction in community spirit as some houses stay empty for long periods and people are without neighbours

Many people have very strong views on second home ownership, as shown in these quotes on the BBC Devon website. Many villages in popular tourist areas such as Devon and Cornwall have seen a signficant increase in properties bought up as second homes. Increasingly young people are finding it difficult to buy homes in the areas they have grown up in due to the rapidly increasing house prices. There have been various calls for the increasing taxation of second home owners to try and reduce the problem. See some of the articles below for specific examples of the problems and some of the solutions that have been proposed. In an exam answer try and name a specific example of an area affected by second homes - e.g. the village of Appledore (Devon).

Key terms check:
Second Home - a home used only at certain times of the year - e.g. weekends / holiday periods

Follow up links:
The impact of second and holiday homes (an interesting research paper - looks at the socio-economic impacts and impacts on the local housing market)
Second Homes squeezing out locals in Scotland (Scotsman Article)
Holiday Homes causing resentment (Devon) (BBC Article)
Tax urged on Second Home Owners (BBC Article)
Second Homes damage village life (BBC Article)
Your views on second homes (Devon) (BBC)
Second Homes (Geography Pages)
Call for more tax on second homes (BBC Article)
Home, Second Home (BBC Article)

Photo Credit: many thanks to Ian Murray - Geography Photos

Counterurbanisation - Causes and Consequences

2007-08-15T08:51:00.001-07:00

Urban to Rural Migration

Since the 1960s there has been a continuing trend of urban to rural migration, with people leaving cities and moving into countryside areas, this process is known as counterurbanisation.

Causes and Consequences of Counterurbanisation

(i) Causes
For your GCSE you will need to understand what is meant by counterurbanisation and you will need to be able to describe the causes and consequences of this process. So why are more people moving from urban areas into the countryside? (the reverse trend of what is happening in many LEDCs where rapid rural-urban migration has been taking place since the 1950s/60s!). The reasons for the movement can be summarised as a set of push and pull factors:

Push Factors (reasons for the movement away from cities)
- higher rates of congestion and pollution
- high land values making it harder for people to find affordable housing
- higher crime rates

Pull Factors (reasons for movements to the countryside)
- perceived better quality of life
- believed to be a safer and more pleasant environment for children to grow up in
- less pollution and more open space
- lower land-values and more affordable housing
- more businesses locating on greenfield sites to make the most of room for expansion and the more pleasant environment.

Improvements in transports and technology have led to the increase in counterurbanisation as it has become easier for people to commute to work or indeed work remotely from home, using internet / fax / e-mail technology.

(ii) Consequences

The process of counterurbanisation has had a number of consequences and in particular has resulted in the changing characteristics of many villages which have seen an increase in population becoming more suburbanised in character. These suburbanised villages have seen various changes as people have moved in from the city. Many have lost some of their rural characteristics as new housing developments have been built and in some instances business units have developed. Village shops and local services often suffer as these settlements often become "dormitory villages", where a large proportion of the population commute to work leaving a small daytime population. Many commuters use large supermarkets on the edge of towns and the lower demand for villages shops and services has forced many to close. There are also social impacts, as once tight-knit communities begin to lose community spirit as more and more people move in.

You should be able to illustrate an answer on suburbanised villages with a case study - e.g.
Peter Tavy, Devon
- experienced the gentrification of existing housing, including several barn conversions
- infrequent bus service (many households with one or two cars)
- need for more low cost housing for young people
- has experienced the closure of local facilities - village shop closed
- increase in newcomers not participating in village life

For more detail on the process of counterurbanisation see the powerpoint below:

Key terms check:
Counterurbanisation - the process of people from cities and towns into the countryside
Suburbanised Villages - villages growing in size and taking on more urban characteristics

Follow up links:
Definition of a suburbanised village

Green Belts - controlling urban sprawl

2007-08-15T08:50:00.000-07:00

To restrict development on greenfield sites (sites that have not previously been built on), urban sprawl has been constrained by the creation of Green Belts. Green Belts were created in 1947 as 'collars of land' around urban areas where development is severely restricted to preserve the character of the environment.

Whilst green belts have successfully slowed urban sprawl, in some cases they may protect land of little value, whilst development 'leap-frogs' the constraints of the green belt and begins to grow on the higher quality land beyond it. Wedges of protected land, as opposed to a surrounding 'collar' have been suggested as a way of allowing controlled growth, whilst protecting high-quality land. Indeed the debate about the future of greenbelts has increased and campaigners are trying to protect greenbelt land.

There are concerns in a number of areas, as further urban development threatens the existing Green Belts. Countryside around both Stevenage and Cambridge is under threat due to plans for the development of new homes, whilst other areas are under threat from other types of development, including plans for a park and ride scheme on the edge of Cambridge.

Case Study: Pressures on the Cambridge Green Belt

In the 1990s, increasing competition for land at the rural-urban fringe to create more jobs and houses, put pressure on green belt areas to release more land.

Cambridge is a famous, historic city with many job opportunities available, easy access to other places and pleasant surrounding countryside. It is protected from urban sprawl by a green belt.

- increase in population have previously been dealt with by increased suburbanisation of villages and the creation of new settlements, e.g. Bar Hill and Cambourne, and the newly designated Northstowe (which begins construction in 2008)
- over the next 15 years, 42,000 houses need to built in Cambridgeshire to accommodate the increasing population - putting great pressure on the Green Belt
- current Green Belt is designed to prevent the mergence of neighbouring settlements, protect the countryside and maintain the character of the city of Cambridge
- review of the Green Belt was carried out in 2001 to assess its present success and areas which could be released for development in a sustainable way
- the current proposal for development includes 8,000 homes on the edge of Cambridge on land currently in the Green Belt
- other options still include, the creation of new settlements and the development of nearby market towns

The key question for debate is whilst provision of new houses is putting pressure on land, should we build on Brownfield sites (areas previously built on which have been demolished) or Greenfield sites (area of countryside, previously never built on)

Why build on Brownfield Sites?
- many areas have unoccupied houses which could be upgraded
- brownfield sites already have utilities such as water and gas pipes
- development in urban as opposed to rural areas can help reduce reliance on cars

Why build on Greenfield Sites?
- cheaper to build on (don't have demolition costs) and lower land-values than in urban areas
- generally perceived as better quality of life in the countryside

Follow up links:
How GreenBelts have benefitted Britain (BBC Video)
"Elastic Band" Green Belt Claim (BBC Article)
Is the Greenbelt an outdated concept? (BBC Article)
Radio 4 News Report - "Is the Greenbelt an outdated concept?"
Warning over Green Belt Hunger (BBC Article)
Is the Green Belt getting 'looser'? (BBC Article)
Green Belt 'at risk of homes' (Gloucesteshire) (BBC Article)
New Developments in the Cambridgeshire Area (linked to Urban sprawl)
Cambridge Green Belt Study
A 'green and pleasant' land (BBC) Article)
Brownfield Land Development

Key term check:
GreenBelts - countryside area around an urban area which are protected from development to restrict urban sprawl
Brownfield Site - an area of land previously build on where developments have been demolished and new building can take place
Greenfield Site - an area of countryside never built on before

Out Of Town Shopping Centres

2007-08-15T08:45:00.000-07:00

Since the 1980s, much of the retail development in the UK has been in the form of out-of-town developments as lower land-values, the availability of land for expansion, a nearby labour force and good access routes on the rural-urban fringe of settlements has encouraged out-of-town centres to develop. These out-of-town centres, contain large, well-known stores and often have attractions for all the family, including leisure facilities, catering outlets etc. The growth of these development has however led to a number of common problems which include:

- traffic congestion in the vicinity of the new developments
- larger stores are often attracted away from nearby town and city centres to these new centres
- more empty shops in town and city centres (often attract vandalism)
- fewer people visiting the city centres - resulting in the creation of a 'dead heart', particularly in smaller market towns and economic decline

City centres have been fighting back against out-of-town developments through 'shop local' campaigns and in 1998, there were calls by the government to stop out-of-town developments, however there have more recently been proposals for relaxing the resulting planning laws which would make it easier for superstores to build out-of-town developments. Other attempts to reduce town centre decline include calls to abolish free car-parking in out-of-town developments to encourage shoppers back to the town centre.

EXAMPLE 1 - MEADOWHALL - Sheffield

Meadowhall shopping centre is a large out-of-town shopping centre that has been developed on the outskirts of Sheffield. It was built in the late 1980s as a response to the lack of shopping provision in the area. It was constructed on a brownfield site (56 hectare site of a former steelworks). Access to the shopping centre is excellent and it is close to several large urban areas with 9 million people living within an hours drive of the centre (see map opposite).

Why this location?

plenty of space for expansion and for providing large free car parks
rates and rents are lower than in the city centre (shops can be bigger) - i.e. cheaper land on edge of Sheffield
near to suburban housing (provides a labour force)
near a number of motorway intersections (nearbly M1/A roads) - great accessibility and access to large sphere of influence
old brownfield site (was a steelworks) with plenty of room for expansion if required

The main characteristics of the shopping centre:

bright and modern with many different faciliites, including a leisure centre, cinema, creche and other attractions for children;
a large variety of shops;
large, free car parts (12,000 spaces!)
provides under-cover shopping (not restricted by weather and shoppers, shop in the comfort of an air-conditioned complex)
supertram link with the city centre;
two new railways stations built

(photo (c) Ian Britton - FreeFoto.com)

The Impact of Meadowhall on Sheffield?
The building of Meadowhall has had an impact on Sheffield City Centre, as many shops have moved out and takings have been down for some shops by as much as 25%. This good article on Geography Pages summarises the issues for the centre.

EXAMPLE 2: BLUEWATER - nr Dartford (Kent)

Bluewater, known as Europe's largest retail and leisure complex, opened in 1999, it was built on a brownfield site, in a disussed chalk quarry and has excellent access, being just outside the M25 in the area of Dartford. The following powerpoint gives more detail about the location and features of the out-of-town shopping centre as well as giving some consideration to the criticisms the centre has come under

Other examples of out-of-town shopping centres include:
Lakeside - East of London
Brent Cross - NW London
Metro Centre - Gateshead
Merry Hill - Dudley (Birmingham)

Follow up links:
Meadowhall Virtual Visit (by Holgate School - good overview)
Superstores 'killing' market town shops (BBC article)
Parking tax on out of town shoppers to save the high street (Times Article)
How has Sheffield City Centre changed since the development of Meadowhall (Geography Pages)
Proposals give supermarkets an easy ride to out of town centres (Time Article)
Meadowhall Website
Bluewater Website

Key Term Check:
Out-of-town Shopping Centres - large retail developments found in out-of-town locations close to major transport links.

The Rural-Urban Fringe (Land-use and conflict)

2007-08-15T08:44:00.001-07:00

The rural-urban fringe (the area at the edge of a city) has become an increasingly popular area for economic developments. Competition for land in these areas increased signficantly during the 1990s. The land is much cheaper here than in the city centre, and many factories that were once in inner city locations have moved to these areas as their previous locations lacked space for expansion. As well as industrial estates and residential use, these areas attract shopping centres, business parks and recreation facilities such as golf courses. The benefits of the rural-urban fringe are set out in the diagram below.

Conflict at the Rural-Urban fringe
Although there is competition for land for economic developments at the rural-urban fringe, there is increasing pressure from environmental groups to restrict urban sprawl and protect the environment on the edge of cities from economic pressures. If urban sprawl continues unchecked, many wildlife habitats would be destroyed. Conservationists and farmers want to protect nature reserves and farmland, and open space for recreation is required by people living in the nearby urban area. There is therefore competition for land at the rural-urban fringe and conflict between economic and environmental land-uses. You should be aware of these and be able to discuss them in an exam answer.

There have been a number of attempts to control urban sprawl and reduce / restrict developments on the rural-urban fringe, these include Green Belts which were created by the government in 1947.

Follow up links:
Rural-urban fringe (definition)
The Rural-Urban Fringe (a detailed article really aimed at A'level students - but with many useful points)
Land-use at the rural-urban fringe (a detailed report from the Farm Foundation summarising policies and issues associated with land-use at the rural-urban fringe)
Urban Land-use Model (GeoBytes)

Key Terms Check:
Rural-urban fringe - where urban areas meet the surrounding countryside
Green Belt - an area of land around a settlement where development is severely restricted
Urban Sprawl - uncontrolled growth on the edge of a settlement
Greenfield Site - land previously unbuilt on

Suburbs - the growth and characteristics of

2007-08-15T08:42:00.001-07:00

THE INNER SUBURBS

Since the early 20th century, cities have continued to grow outwards into the countryside. This is the process of suburbanisation as new residential areas are created at the edge of the city. This new growth surrounded the old industries and low-class residential areas giving them an inner-city location. In the 1920s/30s many of the middle classes moved out of the inner city areas buying houses along main roads / railway routes from the centre (ribbon development)

Reasons for Suburban Growth:

Better public transport and increased car ownership meant people could separate work from where they live
Building societies provided mortgages making it easier to buy homes
People were better off and looking for a better living environment

The continued outward growth of cities is also known as urban sprawl. Early suburban growth (1920s/30s) forms the inner suburbs, as it has now been encircled by further growth (1960s/1980s) which form the outer suburbs.

Characteristics of the Inner Suburbs

Although some inter-war housing was built as estates, ribbon development, laong main roads into the city was common. The photograph below is a typical example of a inner suburban landscape (with housing dating back to the 1920s/30s). Compared to the inner city there is much greater owner-occupancy as people bought their own homes.

The typical characteristics associated with the inner suburbs are shown below (photo courtesey of freefoto.com) :

THE OUTER SUBURBS

Urban Sprawl has continued to enlarge towns and cities, with continued growth at the rural-urban fringe (where the countryside meets the urban area). Residential development on thsi outer fringe forms the outer suburbs. As a result of policies in the 1960s to clear inner city slums, some outer city council estates can be found in these areas.

There are also many private residential estates. Many of these estates were built between the 1960s and 1980s and provide high-quality, low density housing. There is more open space avaialble and a much higher quality living environment. The houses are large and usually either semi-detached or detached. The houses have gardens and garages and are modern in design as well as the amenities they provide. The photograph below highlights the main characteristics that are typical of housing in the outer suburbs.

The typical characteristics associated with outer suburb areas are shown below (photo courtesey of freefoto.com) :

Follow up Links:

Urban Land-use Model (GeoBytes)

Key Term Check:

Inner Suburbs - residential area surrounding the inner city, characterised by semi-detached houses and tree-lined streets
Outer Suburbs - residential area towards the edge of a city, characterised by larger often detached houses and modern housing estates.
Urban Sprawl - the uncontrolled growth of an urban area into the surrounding countryside
Residential - an area of housing

End of Term - Have a great summer!

2007-07-07T09:56:00.000-07:00

With the end of term approaching there will be no more posts this term - however keep an eye out over the summer as the settlement unit will be completed and notes on Coasts will also be added. In September, the weekly updates to the blog will commence! Have a great summer and remember to check out the main Geography website for more resources (www.geobytes.org.uk)

Make your own at ProfilePitstop.com

Settlement Revision

2007-06-06T12:56:00.000-07:00

Revising the Settlement Unit
Having completed the settlement unit, here is a summary of what you need to revise and some resources to help you.

Check list of key concepts to revise:

1. Land-Use zones - you need to be able to describe and account for differences between the characteristics of land-use zones within settlements - remember the zones within the Burgess model - CBD; Inner City; Inner Suburbs; Outer Suburbs; Rural-urban fringe;

2. Conflict at the Urban-Rural Fringe - be aware of the conflicts between land-users at the rural-urban fringe, types of development that locate in this area and strategies to try and reduce urban sprawl, e.g. green belts.

3. Case Study of Urban Regeneration - make sure that you are able to discuss a case study of urban regeneration such as the London Docklands - remember you must be able to give clear locational detail and specific facts and figures to reach the highest marks.

4. Case Study of Urban Traffic Management - remember to learn a case study such as traffic management in Cambridge - again you must be able to give clear locational detail and specific facts and figures to reach the highest marks.

5. Know a case study of the attractions and problems of an out-of-town shopping centre (e.g. Meadowhall, Sheffield)

6. Understand the causes and consequences of counterurbanisation (urban-rural migration), the impact on suburbanised villages and the impact of second homes in relation to changes in village populations.

7. Understand the concept of a settlement hierarchy and the interdependence of a town and its surrounding area (e.g. sphere of influence, threshold population etc.)

8. Make sure you are away of what is meant by the site and situation of a settlement and that you are able to make use of OS map evidence to describe site and situation (this is commonly required in the skills paper).

Revision Resources:
- make good use of your class notes
- make use of blog posts to consolidate your understanding / recap concepts you are less sure of (to access previous posts - use blog archive list on the left hand side of the blog - March-August posts) - remember there are various links to animations etc. to help you.

Interactive Revision Quizzes:
You must learn your notes (particularly case study detail) but once you have revised from your notes there are some interactive revision quizzes etc. here for you to test yourself.

Settlement Glossary Key Word Flash Cards (definition then key word)
Settlement Glossary Key Word Flash Cards (key word then definition)
Settlement Glossary Key Word Quiz
Settlement Crossword Quiz
Settlement Multiple Choice Quiz

(More to be added)

Good Luck Year 11

2007-05-12T08:22:00.001-07:00

GOOD LUCK WITH YOUR EXAMS!

Good Luck to all of Year 11 with their GCSE's. I will be update a few settlement posts on here over half term which may be of help.

Please remember - also see the main revision pages on GeoBytes which you can access here and the Year 11 resources / links from GeoBlogBytes.

Any updates / further resources posted before the exam will be posted here on GeoBlogBytes.

Please e-mail me if you have any questions.

GCSE Revision 1 - Bitesize Resources

2007-04-12T09:45:00.000-07:00

Year 11 and the VI form Geographers are now on countdown to their summer exams. I will be posting links to support the VI form AS/A2 exams over the next few weeks. As a starting point for Year 11 here are a few resources from BBC Bitesize that may help you with your revision. Keep checking back for further links to GCSE revision resources which will be posted here.

Bitesize TV - the popular Bitesize revision programmes are to be repeated in April - you will need to set your video recorders though as they are on very early in the morning!

Bitesize Revision BBC TWO - GCSE Bitesize Geography

Global Issues 26 APR ‘07 02.00 - 04.00 120 minutes
Human geography 25 APR ‘07 02.00 - 04.00 120 minutes
Physical geography 25 APR ‘07 04.00 - 06.00 120 minutes

Geography Audio Topics - the BBC have recently published some podcast style audio clips to help with Geography Revision - they can be downloaded here.

The Bitesize Geography Homepage with revision on a variety of topics can be found here (don’t panic if you see topics here that you haven’t covered - remember different exam boards specify different topics - only look at those you know we have studied).

Thanks to Geography - You’d be Lost Without it for the heads up on the TV schedule!

Inner Cities: Case Study - Regeneration of the London Docklands

2007-03-04T06:10:00.000-08:00

Regeneration of the London Docklands

In the 1980s in an effort to reverse the process of inner city decline the UK government set up Urban Development Corporations (known as UDCs). The aim of these UDCs was to regenerate inner city areas with large amounts of derelict and unuse land by taking over planning responsibility from local councils. These UDCs had the power to acquire and reclaim land, convert old buildings and improve infrastructure through the investment of government money. These UDCs also attracted private sector investment through offering companies reduced taxes and other benefits and in doing so they promoted industrial, residential and community developments.

The London Docklands Development Corporation

During the 19th century, London's port was one of the busiest in the world, but by the end of the 1950s it was in signficant decline with many of the docks derelict and abandoned. In response to the resulting social, economic and environmental problems the London Docklands Development Corporation (LDDC) was set up in 1981.

Why did the London Docks go into decline?
1. An increase in ship size meant they found it difficult to come down the river as far as the Isle of Dogs where the river wasn't as deep. (the position of the docks moved further downstream to Tilbury);
2. Containerisation meant few dockers were needed with large cranes used to lift containers from ships;
3. The decline of portside industries and manufacturing

What were the problems in 1981 in the Isle of Dogs?
* population had declined
* employment was in decline (loss of jobs from decline of docklands
* access to the rest of London was poor with narrow roads which were heavily congested, and a lack of public transport (a single bus route and no rail or underground service)
* 95%+ of housing was rented and including high density terraced houses and large estates dominated by high rise blocks
* Shopping faciliities were limited
* Lack of open space and recreation facilities

Who was involved in helping with the regeneration process?
Whilst the LDDC was responsible for the planning and redevelopment of the Docklands areas, other organisation have also been involved in the redevelopment process, these included:
- National Government - they created an Isle of Dogs Enterprise Zone in April 1982 - offering incentives such as grants, reduced rates etc. to encourage private investment;
- Property Developers - responsible for building large office blocks (e.g. Canary Wharf)
- Local Housing Association - obtained home improvement grants
- Conservation Groups
- Newham Council

Changes to the area between 1981 - 1998

Environmental Regeneration
- network of pedestrian and cycle routes through the area with access to the river and dock edge through waterside walkways
- creation of pedestrian bridges
- creation of new open spaces (150ha)
- Water based Ecology Park and London's first bird sanctuary at East India Dock Basin - one of 17 conservation areas set up
- planting of 200,000 trees;
- the area has now received many awards for architecture, conservation and landscaping

Economic Regeneration
- unemployment had fallen from 14% to 7.4 with a doubling in employment and numbers of businesses;
- transport revolution - opening of the Docklands Light Railway in 1987 - now carrying 35,000 passengers a week;
- £7.7 billion in private secotr investment
- 2,700 businesses trading
- major new roads including link to the M11
- Building of the City Airport in the former Royal Docks (500,000+ passengers a year)
- attraction of financial and high-tech firms,
- TV studios and newspapers such as The Guardian now have offices in the prestigious Canary Wharf business complex.

Social Changes
- £10 million spent on improvement council and housing association homes
- a total of 22,000 new homes built (mainly private ownership with approx 19% for rent)
- conversion and gentrification of old warehouses to new homes
- New shopping centre built - including 4,600sq metres Asda Superstore and refurbishment of shopping parades - also included transformation of old dockland buildings into shopping outlets (e.g. Tobacco Dock)
- Large new shopping centre at Canary Wharf with over 30 shops
- many restaurants, pubs and cafes built
- Docklands Sailing and Watersports Centre
- £100 million spent on health, education, job training etc.

How successful was the London Docklands Redevelopment?

Successes:
- more trade for local shopkeers
- cheaper rents here for large companies yet still the benefit of only being 10 minutes from central London
- a wide range of economic, environmental and social benefits (see above) - including 22,000 news housing units and 1000s of new jobs.
- greatly improved accessibility in and out of docklands
- addressed the once failing land, housing and commercial property markets in the area.

Criticisms:
- there were criticisms that despite the improvements many of these didn't benefit the original 'eastenders' - click on the photo opposite to see some of the 'anti-LDDC' graffitti
- many locals were unable to afford the high costs of the new expensive houses / flats (still a lack of low-cost housing in the area)
- despite an increase in jobs with new businesses coming in, most required skills that the old dockers did not have;
- reduction in community spirit that the old Docklands had - with the 'yuppie' newcomers not mixing with the eastenders

Follow Up links:
Virtual Tour of the London Docklands (excellent site from Wycombe High School - well worth looking at!)
London Docklands Quiz
LDDC - Isle of Dogs - excellent overview of what has been done in terms of regeneration
About LDDC (Royal Docks Trust)- good overview looking at what the LDDC was, the task, what its achievements were and how successful it was
London Docklands Development Corporation (Wikipedia)
London Docklands Overview (Wikipedia)
London Docklands Case Study (Internet Geography)

Photos credit and sources:
1. I Murray from http://www.geographyphotos.com/ 2. JP Raud Dugal from http://www.geographyphotos.com/
3. A Stacey from http://www.geographyphotos.com/ 4. I Murray from http://www.geographyphotos.com/
5. IMurray from http://www.geographyphotos.com/

Inner Cities: Solving the problems - Urban Renewal

2007-03-04T05:38:00.000-08:00

Urban Renewal / Urban Redevelopment

By the 1960s, the inner cities has fallen significantly into decline (see previous post). The old terraced houses and the old tenement buildings in Scotland (see photograph) were run down and lacked modern amenities. In response to the problems associated with the decline of the inner city, urban renewal and redevelopment began in the 1960s with many areas in the UK's inner cities being cleared. In their place, multi-storey tower blocks were built. Unfortunately these flats were not as successful as they were designed to be. Despite the better access to modern facilities such as running water and indoor bathrooms, which had been absent in many of the old terraced houses which had been demolished, further social problems were created. The diagram belwo outlines some of the perceived advantages and the problems that were associated with this 1950s/60s urban renewal.

Photo Source: VVannet from www.geographyphotos.com

Urban Land Zone 2: The Inner City

2007-02-25T06:38:00.000-08:00

What is the Inner City?
The Inner City is the land-use zone which grew up around the city centre, it is also known as the twilight zone or zone of transition.

When did the Inner City grow up?
Inner city areas grew up in the 19th century as towns grew rapidly due to industrialisation and the demand for workers in the industries that had grown up. Large numbers moved to the city for work and needed low cost housing close to work due to the lack of public or private transport. This led to the growth of factories and low-cost terraced housing around what is now the city centre.

What were the characteristics of the Inner City?

* crowded areas with little open space
* high density housing (overcrowding)
* mainly terraced (some used to be back to back houses (back wall of one house being the back wall of another)) in long straight rows
* front doors opening straight on to the pavement
* no front or back gardens (just a small back yard)
* few amentities
* factories providing employment for residents

Advantages of living in the Old Inner Cities:
1. Houses were cheap to buy / rent
2. There was a strong community spirit
3. Houses were close to places of work

Problems in the Old Inner Cities
1. Housing - decayed terraces and in places poorly built tower blocks
2. Pollution - air, land and water pollution, graffiti and vandalism and derelict buildings (old factories etc.)
3. Lack of Open Space
4. Social Problems - high crime rates, above average concentrations of low-income citizens
5. Economic Problems - declining industry, povery and low income and increasing unemployment as factories closed.

The Changing Inner City
By the 1950s/60s, many inner cities were in series decline as the traiditional industries has closed, resulting in high levels of unemployment and a subsequent spiral of decline (see diagram for explanation). Since the 1960s, the Inner City zone has been one of change (hence the terms twilight zone / zone of transition) with a number of schemes (urban renewal, urban regeneration and urban redevelopment) put in place to address the issues of decline and to improve the quality of life in these areas. (see next post for more details)

Follow up Links:
GeoBytes Land-use model: Inner City

Key Term Check:
Inner City - part of an urban area next to the central area / CBD (characterised by housing and industry) - also known as the zone of transition or twilight zone.

Photograph Source: Geography Photos (www.geographyphotos.com)

Urban Land Use Zones: Managing Problems in and around the CBD

2007-02-25T04:04:00.000-08:00

There are a number of problems faced in the Central Business District area:

1. Lack of Space and High costs of Land
Due to the accessibility and prime location of land in the CBD, the resulting high density land use and competition for available buildings means that the costs of land and consquently rents are very high. National chain stores therefore dominate these areas as they are able to outcompete smaller, independent stores which cannot afford to pay such high rents.

2. Urban decline
With the growth of out-of-town shopping centres, some CBD's have seen the outward movement of many of the larger stores to take prime sites in these out-of-town complexes where there is room for expansion. The cheaper land in these suburban locations also enables stores to operate on a larger scale and pass on the benefits of economies of scale to customers (for more on this see this excellent article from Geography in the News). As stores move out, this has led to the decline of some CBD's. Shop units made vacant by large chain stores moving out, may stay empty as smaller / independent stores cannot afford the high land rents, whilst other chain stores are preferring to locate in the out-of-town locations. Empty buildings can attract crime and vandalism and gradually CBD's affected by this start to suffer urban decline.

General Urban Problems

1. Pollution
With the high volumes of traffic and congestion and the high numbers of pedestrians using the central area, problems of noise, visual and atmospheric pollution have become an issue in some CBDs.

2. Traffic Congestion
With the great accesibility of the CBD and the increase in car ownership, urban traffic problems have become a real issue in many cities.

A Case Study of Traffic Management in an Urban Area: Cambridge

As part of the syllabus you are expect to know a case study of manging problems in urban areas. Our case study is Traffic Management in Cambridge.

Before we look at Cambridge specifically, lets consider the general causes and effects of Traffic problems in urban areas.

Why has Traffic in urban areas increased?
* increased car ownership (due to an increase in disposable income)
* reduced use of public transport
* an increase in commuting (for work, shopping, entertainment etc.)

What are the problems that result?
As well as the problems of visual, atmospheric and noise pollution, the environment is also affected as more land is required to build car parks, widen roads and build new roads to cope with the volumes of traffic. Congestion resulting in traffic jams can significantly delay travel times and result in people being late for work as well as valuable time being wasted whilst trying to locate parking spaces etc. An increased risk of accidents, health problems resulting from the increased fumes (particularly irritating respiratory illnesses such as asthma) and increased frustration / discomfort from overcrowding on public transport are some of the social problems experienced.

Traffic Management in Cambridge
So what is the specific problem in Cambridge and what is being done to try and manage the traffic in Cambridge? Although you will need to refer to your class notes for details, see the powerpoint below for a reminder of the key points of this case study.

Other Traffic Management Strategies

The London Congestion Charge has been in place since 2003. Although there the benefits of the scheme have been recognised - there have also been criticisms with reference to the impact of the charge on businesses. With the recent doubling in size of the London Congestion Charge zone there has been much in the news recently on proposals for 'road pricing' nationally.

Follow up links:
Technology and Traffic Management: London Case Study
Technology and Traffic Management: Global Case Studies
Reducing Congestion in Cities (BBC Bitesize)
An interesting article here on the London Congestion Charge and implications for other cities
UK's congestion schemes (BBC)
How would road charging work? (BBC)

Urban Land-use Zones: 1. The CBD

2007-02-12T10:13:00.001-08:00

Zone 1 in the land use models is known as the Central Business District (CBD). The CBD is at the heart of a town or city and usually has great accessibility as it is often the place where most road and rail routes meet.

So what are the main characteristics of a CBD? Have a look at the following powerpoint - look at the photographs in the first 4 slides for clues and then continue to see what characteristics they are actually showing.

CBD Characteristics
You will need to be able to describe and where appropriate explain the main characteristics of the CBD. Where possible always try and give examples related to areas you know (e.g. Cambridge and St Ives)

- Old Core - often narrow streets / historical core (e.g. The Backs in Cambridge)
- Very Accessible - due to the convergence of major rail and road routes (often find public transport meets here - e.g. railway stations / bus stations)
- Traffic Restrictions are often in place to deal with the large numbers of traffic and ensure safety for the high numbers of pedestrians.
- Often has a central Market square area (e.g. Cambridge and St Ives)
- Very High Land Values - due to lack of space and competition for land
- Little/ No Residential Land Use - due to high land-values there is usually no residential land-use apart from the possibility of some flats above shops
- Multistorey buildings - due to high land values resulting in building up rather than out!
- Shops Offices and specialist buildings e.g. Banks, buildings societies etc. (need to be accessible and can afford the high land values)
- Mainly National Chain stores (have high threshold population and can afford the high land-values associated with the CBD - e.g. M&S; WHS; Next etc. in Cambridge)
- High numbers of pedestrians
- 2 daily rush hours (am and pm)
- Many now have undercover shopping centres (e.g. Lion Yard - Cambridge)
- Presence of public buildings / government buildings (e.g. Town Hall etc.)
- museums / castles / historical buildings (e.g. Cambridge - museums / University buildings)
- Entertainment - restaurants, clubs etc.

Follow up Links:
Central Business District (Wikipedia Entry)
BBC Bitesize (Central Business District)

Key Term Check:
Threshold Population: minimum number of people needed to justify the provision of a service or presence of a certain shop
CBD: Central Business District

Urban Land Use Models

2007-02-12T08:34:00.000-08:00

Land-use models have been put forward on the basis of the idea that towns and cities do not grow in a haphazard fashion, rather they tend to develop distinctive patterns of land-use as they grow and develop. Land-use models are simplified diagrams which are used to represent the pattern of land-use functions within a town or city. It should however be remembered that these are simplifications of reality and it is unlikely that any model will fit every town and city perfectly.

Two of the land-use models we often refer to are the Burgess Concentric Ring Model and the Hoyt sector model

The Burgess Model
This model was based on a study of land-use in Chicago. Burgess suggests that cities grow outwards from the CBD in a series of concentric rings of land-use. The oldest part of the city is at the centre and the newest part on the outer edge. The quality and size of housing increases with distance from the CBD, although the height of buildings tends to be greatest close to the Central Area, where land-values are high and space is at a premium. The quality and size of houses increases with distance from the CBD but the density of housing decreases as more space is available.

The Hoyt Sector Model
Hoyt's model modified that of Burgess following the development of public transport. His model suggests that transport and physical features were important, with industrial areas developing outwards in sectors along main transport routes (roads, rivers and canals) and housing growing up around these.

The Land-use zones identified in the models are:
1. CBD (Central Business District) - located at the centre of the city often at the convergence of rail and road routes. Contains many commerical activities, shops, entertainment and also business activities.
2. Inner City (also known as the Twilight or Transition Zone) - mixed land-use containing small industries as well as high-density residential land-use - often characterised by terraced housing.
3. Inner Suburbs - residential areas which developed during the 1920s/30s - often semi-detached houses in a distinctive 1920s/30s style with bay windows and front / back gardens.
4. Outer Suburbs - residential areas which grew up later as greater public transport and private car ownership allowed people to live further out from their places of work. These houses are often semi-detached / detached with larger gardens and garages.
5. Rural-urban fringe - this is right on the edge of towns and cities and is mainly low density, private housing (often larger detached properties); new industrial estates / business parks and facilities requiring larger open spaces such as golf courses;

It is important that you have a good understanding of the reasons for the growth and development of each of the land-use zones and that you are able to describe their main characteristics. In an exam you may be given maps or photographs and be expected to suggest which land-use zone they represent based on the features that can be seen (i.e. based on style of housing, density etc.).

Land-Use in Cambridge

Cambridge is a good example of a city with distinct urban land-use zones. The city stands on the east bank of the River Cam and developed here as it was an area of flat land and at the lowest bridging point across the river.

The city itself dates back to Roman times and has steadily grown up as an important trading centre and an important University town. In the centre of the city close to the historic core, as well as the old university buildings, which dominate, the land-uses are mainly commercial, and business in the CBD. One of the most important developments in the growth of Cambridge was the coming of the railway which was built in 1845. At this time residential areas began to expand more rapidly, with early Victorian terraced housing (inner city zone) which began to be developed out towards the railway station to the east of the city.

In the 20th century, the population grew even faster and houses were built along the main roads which converged on Cambridge. This is known as ribbon development. The houses were often inter-war semi-detached houses and now began to be built with garages as car ownership began to increase (inner and outer suburbs). This meant that now villages such as Cherry Hinton were being incorporated into Cambridge. This is known as suburbanisation.

Since the 1960's, modern housing estates have also grown up around the city. Some are council built, such as some of the houses at Kings Hedges while others are privately owned. (rural-urban fringe developments)

Follow Up Links:
The Burgess Urban Land-use Model - a detailed overview of the model and some of its criticisms
Urban Land-use patterns in MEDCs
BBC Bitesize - Urban Land-use Models
S-cool - Urban Morphology

Key Term Check:
Burgess Model - concentric ring model based on rings of land-use grown outwards from the CBD (with oldest buildings in the centre of the city, decreasing with age with distance from the CBD whilst wealth of inhabitants increases with distance)
Hoyt Model - sector model - wedges of land-use development determined more by major transport routes.

Settlement - Site and Situation

2007-02-12T08:30:00.000-08:00

Site and Situation

When we talk about the site of a settlement, we are refering to the land on which the hamlet, village, town or city is built. A number of site factors would have been important when choosing the inital site of a settlement. These would have included the relief of the land; the availability of natural resources; water supply and the fertility of the surrounding land.

We also talk about the situation of a settlement, this is the location of a place relative to its surroundings (which may include other settlements, landscape features such as rivers, uplands etc.)

The Site and Situation of St Ives (Cambridgeshire)

Image produced from the Ordnance Survey Get-a-mapservice. Image reproduced with kind permission of Ordnance Survey and Ordnance Survey of Northern Ireland.

The Site of St Ives

St Ives is on a gravel terrace on the North bank of the River Great Ouse and it is located at a bridging point of the River. There is a floodplain to the south (Hemingford Meadows). The town itself is built mainly on flat land and is surrounded by fertile land. There is an area of woodland close to the old part of the town.

The Situation of St Ives
The settlement of St Ives is situated approximately 17miles to the North West of Cambridge and is about 5 miles east of the market town of Huntingdon. St Ives is just North of the A14 on A1096 it is situated north of the River Great Ouse.

You should know the difference between site and situation and you should be able to describe the site and situation of a place such as St Ives. In the skills paper you will also be expected to interpret OS maps of places you haven't studied before and you will need to be able to identify and describe the site and situation of these places. Have a look at this excellent page from BBC bitesize and see if you can identify the features of the site of Southampton from the OS map provided - why was the city located here? Also check out the OS map of Melton - read the example of the description of its situation that is given.

Follow Up Links:
Settlement Site and Situation (BBC Bitesize)
Site and Situation of a Settlement (good example of Edinburgh) (BBC Scotland - Bitesize)
S-Cool - Site and Situation (Physical and Human factors important in settlement location)
Site, Situation and Function (Digital Brain)

Key Terms Check
Site - the land on which a settlement is built
Situation - the location of a place relative to its surroundings.

People & Places to Live: Settlement

2007-02-12T08:29:00.000-08:00

Urbanisation - An Introduction....

The increase in the population of towns and cities is known as the process of urbanisation. In MEDC's such as the UK, urbanisation occurred alongside the industrial revolution of the 18th century, with millions of workers being attracted to the new factories and houses built in towns and cities. Urbanisation in LEDC's has however been a far more recent phenomenon, with rapid urbanisation having been experienced since the 1950s. This excellent interactive timescale graphic from the BBC shows the scale of urbanisation across the world since 1955.

It has been projected by the UN that world population will expand from 6.1 billion to 7.8 billion between 2000 and 2025 with 90% of the gowth occuring in urban areas or less developed countries (Population Reference Bureau). In 1800, only 3% of the world's population lived in urban areas, by 2000 this was estimated to be 47% and according to the Population Reference Bureau it is projected to reach 58% by 2025!

In this unit of the course, we will explore the growth of settlements in both MEDCs and LEDCs, looking at the reasons for, and changes in their growth and development as well as the resulting problems. We will also consider the patterns of land-use that have developed and some of the issues faced in managing these urban areas.

Follow Up Links:
Urbanisation in the Nineteenth and Twentieth Centuries - an excellent site - well worth having a look!
BBC InDepth - Urban Planet (some fascinating articles here!)
An overview of Urbanisation (Internet Geography)
An Urbanising World (Population Reference Bureau)
In Pictures: the shrinking space in our crowded cities (BBC)
Urbanisation - Wikipedia Article
Are cities growing too fast?

Key Terms Check:
Settlement - a place where people live
Urbanisation - an increase in the numbers living in urban areas (towns and cities)

Photo Source: Val Vannet on Geography Photos

Young Geographer of the Year 2007

2007-02-12T04:18:00.000-08:00

The new competition for Young Geography of the Year 2007 has just been launched by the Geographical Magazine.

This year's question is "Can Recycling Save the World?" and must be the title of any work that is submitted for the competition. There are 3 different categories for the competition:

* Junior (12 and under on 31st August 2007) - design a magazine front cover (A3 size)

* Young (13-15 on 31st August 2007) - write a magazine article (word limit: 800 words)

* Senior (16-18 on 31st August 2007) - write a magazine article (word limit: 1600 words)

There are some amazing prizes on offer for the winner of each category. Have a look at the following:
- Winner of the Junior Category - a Raleigh Max bike.
- Winner of the Young Category - a fortnight placement with a guardian to work on a conservation project with desert elephants in Namibia.
- Winner of the Senior Category - A month long Amazon expedition in Peru(23rd July - 24th August 2007 - prize is not exchangable - see site for more details) "Research projects on this expedition will include surveys of both the pink and grey river dolphins, building hatching sites for turtles and surveying populations of animals such as the red howler monkey" (www.geographical.co.uk)

For full details of the competition and the prizes on offer please see the competition pages of the online Geographical Magazine. Terms and conditions of entry can be found here.

If you are interested in entering the competiton, please see me with your ideas. If you decide to enter, once you have completed your entry you will need to see me for an entry cover sheet.

Why not post some of your thoughts on the question "Can recycling save the world?" by adding a comment to this post. . .

Here are a few links which may help you with your research - there are lots of others out there...

- See the short "Recycling: The Issues" post on here
- Environment Issues: Recycling
- Recycling saves our environment
- Recycling and Waste - includes some facts and figures (DEFRA)
- Earth 911
- Recycle Now
- Recycling - Wikipedia Article
- Recycle-more

Plate Tectonics Revision

2007-01-28T11:21:00.000-08:00

Revising the Plate Tectonics Unit
We have now come to the end of the Plate Tectonics Unit and its time to revise!
Here are some resources to help you.

Check list of key concepts to revise:

1. Structure of the Earth - what are the four main layers of the earth
2. Plates - named examples of plates and reasons for plate movements (convection currents)
3. Plate Boundaries - make sure you learn the four main types of plate boundaries. For each you need to be able to (i) describe movement of the plates (ii) explain what happens - processes and landforms created (iii) named example of each.
4. Distribution of earthquakes and volcanoes - be able to describe the distribution - linked to plate boundaries and examples (remember the anomaly for volcano distribution is the Hawaiian Islands in the middle of the Pacific Plate - due to hotspot activity)
5. Volcanoes - what are volcanoes? What are the key characteristics of a volcanoes structure?
6. Where do volcanoes occur? (be able to talk through what happens at a destructive and constructive plate boundary resulting in volcano formation)
7. Case Study of a Volcanic Eruption - Mount St Helens (Cascade Range, USA 1980) - learn causes, effects and responses (remember you must learn specific facts and figures and be able to show locational knowledge to get the highest marks)
8. Why do people continue to live near volcanoes? (be able to illustrate with examples)
9. What techniques are used to monitor and predict volcanic eruptions?
10. Earthquakes - theory of formation and key terms
11. Case Study of an Earthquake - San Francsico Earthquake - 1989 - again learn causes effects and responses (and as before you must learn specific facts and figures and be able to show specific locational knowledge to get the highest marks)
12. Why do some earthquakes cause more damage than others? - be able to compare MEDC / LEDC earthquakes (learn facts and figures for Bam 2003 earthquakes - to compare with 1989 San Francisco earthquake)
13. How can we monitor and prepare for earthquake activity?

Revision Resources:
- make good use of your class notes
- make use of blog posts to consolidate your understanding / recap concepts you are less sure of (to access previous posts - use blog archive list on the left hand side of the blog - Dec/Jan posts) - remember there are various links to animations etc. to help you.

Interactive Revision Quizzes:
You must learn your notes (particularly case study detail) but once you have revised from your notes there are some interactive revision quizzes etc. here for you to test yourself.
Plate Tectonics Glossary - Key word flash cards (definition then word)
Plate Tectonics Glossary Key word flash cards (word then definition)
Plate Tectonics Glossary - Key Word Test
Plate Tectonics Crossword Quiz
Tectonic Activity (Penalty Shoot out) - Hull Trinity House school
Yr 10 Plate Tectonics Revision (Penalty Shoot out)
Plate Tectonics Quick Quiz (Multiple Choice)

Case Study of an Earthquake in an LEDC - Bam 2003

2007-01-28T11:20:00.001-08:00

Bam, the ancient historic city in Iran, was hit by an earthquake measuring 6.6 on the Richter scale on December 26th, 2003 resulting in the deaths of over 43,000 people and leaving over 60,000 people homeless. Many of the mud-brick buildings in Bam collapsed resulting in the high loss of life. The mud-brick disintegrates easily into rubble, making rescue difficult and hopes of survival low. The survivors had not only lost friends and family, but their homes and everything else they had. Many were left destitute on the streets, some forced to spend the cold nights wrapped in blankets; whilst some were given tents, others made use of any shelter they could find. 90% of the buildings in the ancient citadel was completed destroyed (photo shows view over the city prior to the quake.

After the quake there was criticism of the coordination of relief efforts by the government and of the lack of preventative measures. The Iranian press spoke out about the controversy surrounding this and the lack of a national plan to make buildings quake proof. Read more about this in this excellent article from the BBC. One of the big criticisms by the domestic press and independent organisations at the time was over the sub-standard housing (with many people dying in collapsed buildings) calling into question the role of the Minister for Housing.

Following the quake in Bam, 'tented cities' were constructed on the outskirts of the city by relief workers to try and house the many homeless. Many survivors were however reluctant initially to leave the sites of their destroyed homes with family members, friends and property still buried. As well as battling to survive in the below freezing temperatures of the Iranian winter, one of the concerns at the time was over the lack of access to decent sanitation, with many sharing outside toilets and a lack of clean water. However, ironically it is believed that the freezing temperatures may have actually helped to reduce the incidence of water bourne disease expected. With large numbers of volunteers coming in from all over Iran after the quake, the main plea for help after the earthquake was for medicine and equipment to help the tens of thousands injured in the quake.

You need to be aware of the reasons for differences in earthquake impact between countries at idfferent levels of development and you need to be prepared in an exam to discuss the differences with examples. So why was the death toll of the Bam earthquake so high? See this excellent articles from the Guardian "Dangerous buildings, lax rules: why Bam death toll was so high" and "Why did so many have to die in Bam?"

Here is a summary of some of the reasons for the high death toll (see article and links below for further detail)

- poor construction of buildings
- lack of earthquake proof buildings
- buildings made of mud-brick (collapse easily into rubble)
- lack of enforcement of building codes / regulations
- lack of research into techniques to protect the buildings from earthquakes
- population boom and competition for houses (resulted in rapid building of sub-standard housing)
- lack of national plan for the event of a disaster
- extreme cold temperatures made conditions for survivors difficult

To find out more about the quake, including the effects and considerations as to why the effects may have been so severe try exploring some of the following links and news stories:

- Twin Earthquakes - comparing the California and Bam earthquakes of 2003
- Why did the Bam Earthquake Happen (some excellent links thanks to Noel Jenkins of Court Fields School)
- Preliminary report on the Bam Earthquake - Iran
- Bam: Iran's Ancient City (includes photographs and further information)
- Lessons learnt on the national and international response to the Bam earthquake
- Iran Earthquake - Preliminary Reconnaissance (Using Remotely Sensed Data the Views (Visualising the impacts of earthquakes with satellite images) system) - some amazing before and after images here). and also a very detailed report here ICG Report - Bam Earthquake - December 2003

News Stories from the time (BBC News)

The Earthquake: Causes / Effects / Responses:

Bam: Jewel of Iranian Heritage

Tending to Iran's shattered City
Iran battles to cope with disaster
Concealed fault caused Bam quake
Starting from scratch in Bam
Iran lowers Bam earthquake toll
Rebuilding Bam 'could cost $1bn'
Iran considers moving capital
Bam: a year after the earthquake (includes video clips)
Iran quake survivors battle cold

Rescue Missions / Helping the people of Bam:
Helping the people of Bam (work of aid / relief workers to help survivors)
Devon rescue team on Quake Mission
Helping the people of Bam
Woman helps reunite quake survivors (story of a red cross worker)
Iran Earthquake - How to help (what was needed in the immediate aftermath - who helped?)
Earthquake Rescue (audio tale of Phil Haigh who has been working in Disaster Relief since 1968)
Response to the Earthquake / Controversy over lack of Preparedness:
The politics of earthquakes
Iran press lambasts quake efforts
Tough questions over Iran quake
Press tackles Iran over quake
Earthquake angers Iran media
Survivors recall Iran quake loss

Pictures:
In Pictures: Bam before and after
In Pictures: Symbols of Hope
Your Pictures: Bam after the earthquake

Original source of photo: http://commons.wikimedia.org/wiki/Image:BAM_IR2726.JPG

Comparing Earthquakes

2007-01-20T07:30:00.003-08:00

Why do more people die in some earthquakes than others?

One of the crucial factors in determing the severity of the effects caused by an earthquake is the magnitude of the quake. The magnitude of an earthquake is measured on the richter scale, which is logarithmic (hence each level of magnitude is 10 times greater than the one before it on the scale). However, magnitude is not the only factor to be taken into consideration; indeed in December 2003 - 2 quakes of a simillar size resulted in very different death tolls - in California 3 people died in a quake measuring 6.5 whilst around 40,000 died in Bam (Iran) in a quake measuring 6.6. So why do some earthquakes result in more fatalities than others? What are the factors which contribute to the severity of the effects of a quake?

1. Location of the Epicentre

The epicentre is the point on the surface directly above the focus (start of the earthquake). It is at this point where the energy from an earthquake is usually at its greatest. The distance from the epicentre therefore has a big impact. The epicentre of the 1989 San Francisco earthquake was around 80km from San Francisco whereas in the 2003 Iranian earthquake, the epicentre was very close to the city of Bam (accounting for the high death toll)

2. Level of development of the Country

Earthquakes which occur in the richer countries of the world often have fewer fatalities simply due to the greater state of preparedness which is facilitated by the greater amount of money available to put into earthquake research, monitoring and preparation. You should be able to compare examples of earthquakes in MEDCs and LEDCs (see posts on the San Francisco 1989 quake and Bam 2003 quake - both of which were around 6.6-6.9 on the richter scale yet with vast differences in the number of fatalities - 67 in the San Francisco quake compared to around 40,000 in the Bam quake).

Some examples of reasons for an often greater death toll in LEDCs:
- buildings are often not earthquake proof and may be built out of flimsy materials not suited to quakes (e.g. mud brick used in Bam); with pressures on population, buildings are also often built quickly and as a result are often sub-standard and not built to meet building codes;
- emergency services in LEDCs are usually not as well funded and therefore not as able to cope, due to fewer training opportunities and less money for essential equipment / supplies;
- lack of money for prediction technology and monitoring of sesimic activity
- many LEDC cities are very densely populated with houses packed close together, resulting in great danger from collapsing buildings and the rapid spread of fire;
- in some LEDCs, difficult political situations can mean response to earthquakes by government officials is not as quick as it should be.

Also have a look at this interesting article from the BBC "Can money stop an earthquake?"

3. Time of the Day / Time of Year

If an earthquake occurs at night, most people are in bed. In areas where buildings collapse easily this can result in a higher death toll, although in areas where fewer buildings are likely to collapse and where deaths are often higher due to collapsing roadways / falling debris, fewer people may die if the quake occurs at night. The time of year can also be important due to seasonal differences in temperature which can exacerbate the effects of a quake. Following the Bam 2003 quake almost 60,000 were left homeless, forced to take shelter in simply blankets and makeshift tents in freezing evening temperatures. Where conditions are much warmer, this can facilitate more rapid decay of bodies and lead to an increase in the spread of disease following a quake, particularly in areas where access to clean water is poor.

4. Population Density

An area of dense population is likely to experience more deaths than a rural area simply due to a greater liklihood of people being affected by the quake and more buildings, road networks and bridges which may collapse. A major difficulty however in earthquakes which occur in rural areas is getting rescue teams and aid to the affected areas.

5. Land that buildings are constructed on

Where buildings are constructed on soft granular sediments or areas of landfill, the effects of an earthquake maybe more severe due to the process of liquefaction. This process, which results in ground failure, occurs when ground shaking causes water to rise, filling pore spaces between granular sediments, increasing pore water pressure and causing the sediment to act as a fluid rather than a solid. This can result in the collapse of overlying buildings, roads etc., such as occured in the Marine District in San Francisco during the 1989 quake due to it being built on landfill from the 1906 quake (see this excellent article on liquefaction in earthquakes for examples)

Likewise, if earthquakes occur in areas with steep surrounding slopes, ground movements can trigger landslides causing great loss of life.

For further information there is an excellent article on "The Geography Site" called "What determines the impact of an earthquake?" - has a good level of detail and lots of examples - well worth reading! Also see this article Factors that Affect Damage in an Earthquake for information on effects and factors that can affect them.

Key Term Check:
Liquefaction - where sediments act like as a liquid rather than a solid due to ground shaking causing water to rise and increase pore water pressure.
Epicentre - the point on the surface directly above the focus
Focus - the point at which an earthquake starts
Magnitude - this refers to the strength of an earthquake and is measured on the Richter Scale

Preparing for Earthquakes

2007-01-20T07:29:00.000-08:00

Earthquake Preparedness

Can we predict earthquakes?
Although we cannot predict the exact timing of an earthquake and they can occur unexpectedly, we can undertake monitoring of seismic activity to try and determine where earthquakes are most likely to occur and to try and provide some sort of forecast to ensure preparations can be made where possible to try and minimise death and damage caused. This includes:
- using special instruments to measure / monitor possible earth movements (use of seismometers / seismographs)
- plotting the regularity of earthquakes to look for possible patterns
- mapping centers of earthquakes to indicate where earthquakes may be overdue and where pressure may be building up
- observing natural phenomena which can sometimes indicate the likelihood of earthquake activity (odd animal behaviour has been acknowledged - for example snakes in China as indicated in this BBC article also see this National Geographic article Can animals sense earthquakes? )

There is an excellent article on Earthquake Prediction on the Geography Site here.

Preparing for Earthquakes
There are many things that can be done to take precautions and prepare for the event of an earthquake in order to try and minimise any potential damage. These include..

- Monitoring ground movements - to identify possible seismic activity (as discussed above)

- Earthquake proof modern buildings - this may include reinforcement of foundations; counter-weights; and use of fireproof construction materials. (see here for animation on buildings resisting earthquakes)

- Building Regulations - avoid building on unstable ground (such as landfill) to avoid liquefaction

- Practice Disaster Routines - annual earthquake drills - e.g. San Francisco - April 18th (also see this news article on Japan's quake drill)

- Automatic shut off switches - for gas mains - to try and minimise the likelihood of fire

- Public Education - public information posters / information on emergency procedures / preparing house / survival kits etc. (e.g. Is Your Home Protected from Earthquake Disasters?)

- Strengthen Routeways - strengthen foundations of bridges / suspended roadways etc.

- Emergency Service Planning - ensure emergency services (medical and rescue) are fully trained to cope with such a disaster and that specialist emergency equipment is available.

Earthquake Case Study: 1989 San Francisco Earthquake

2007-01-20T05:19:00.001-08:00

On 17th October 1989, at 5.04 pm, an earthquake measuring 6.9 on the Richter scale, and lasting only 15 short, but devastating seconds, hit San Francisco (see shake intensity map) The following YouTube video gives an overview of some of the images of the aftermath of the earthquake. You will need to learn the case study of the San Francisco Earthquake. You need to have an understanding of both the causes of the quake and its effect on people, the environment and the economy.

Cause of the 1989 San Francisco Earthquake

San Francisco is located on the San Andreas Fault Line which marks the boundary between the North American and Pacific Plate (a conservative Plate boundary). As the two plates move past each other, pressure builds up due to friction. The earthquake occurred due to the sudden release of the built up pressure. The epicentre of the earthquake was under a mountain known as Loma Prieta, 10 miles NE of the city of Santa Cruz. The 1989 earthquake (measuring 6.9 on the richter scale) was the largest earthquake to have hit California since the 8.2 earthquake of 1906. This movie, shows the shaking intensity and movement of seismic waves during the 1989 quake.

Effects of the 1989 San Francisco Earthquake

The effects of the 1989 earthquake included:
- 67 Deaths
- 6,000 Homes damaged / destroyed
- 2000 people made homeless
- Upper deck of the Nemitz highway collapsing onto the lower deck crushing people in their cars
- A section of the San Francisco-Oakland Bay Bridge collapsing
- Fire resulting from gas explosions
- Massive economic costs ($4.4 billion)
- Damage to infrastructure - electricity / gas and water mains cut

3 Areas in San Francisco were p articularly badly affected:

1. The Marina / Bay District
Here the buildings were wooden and not securely attached to their foundations. The area was also located on an old landfill site, which was created following the devastation caused by the 1906 earthquake. As a result of the weak sub-surface sediments, when the ground shook in the 1989 earthquake, the process of liquefaction occured. This is where as the ground lost its sheer stength and acted more like a liquid as water moved up through the sediments resulting in reduced strength and causing buildings to collapse due to lack of support.

2. Collapse of the Double-Decker Nimitz Highway and San Francisco-Oakland Bay Bridge

A number of roadways were damaged during the earthquake, including the collapse of the upper tier of the double-deck er Nimitz Highway (Interstate 80) onto the lower deck, killing and trapping motorists in their cars. The collapse was caused partly by soil faiture and also the unsuitable design of the supporting piers. A section of the Bay Bridge also collapsed killing motorists.

3. Older Buildings of Downtown San Francisco

Many of the older (50-100 year old) buildings which were not designed to withstand earthquakes were most severely damaged. Low rise building were also worse affected than taller buildings which swayed with the quake / ground motions.

Follow Up Links:
Remember to get full marks in a case study answer you need to learn specific facts and figures and include locational detail (i.e. name specific places, areas, buildings etc. affected). As well as class notes, see the following links for further detailed information on the 1989 quake.

1989: Earthquake hits San Francisco (BBC - On this day)
San Francisco Virtual Museum - 1989 Earthquake Reports and Photographs
1989 San Francisco Earthquake Photographs
Wikipedia - Loma Prieta Earthquake
The October 17, 1989 - Loma Prieta, California Earthquake (USGS)
USGS Summary - 1989 Loma Prieta Quake

Key Term Check:

Liquefaction - where the ground begins to act like a liquid during an earthquake
Focus - the start of the earthquake underground
Epicentre - the point on the grounds surface directly above the epicentre

Earthquakes

2007-01-20T05:17:00.000-08:00

The cause of Earthquakes

Earthquakes are sudden ground movements which result from the sudden release of built up energy. This energy is released in the form of seismic waves. Earthquakes are caused due to tectonic motions in the earth's crust. Earthquakes are found at all four of the major plate boundaries (constructive, destructive, collision and conservative boundaries), due to the forces of collision between plates as well as the irregular movement and build up of friction as plates move past each other. Earthquakes also occur away from plate boundaries at weaknesses in the earth's crust known as faults.

As plates move past each other, friction between them results in the build up of pressure. As the plates continue to move and the pressure builds up, eventually the pressure is great enough to overcome friction and the plate jolts forward releasing the pent up energy in the form of seismic waves. The point at the rocks break apart and shock waves start is known as the focus of the earthquake. The point on the surface directly above the focus is known as the epicentre of the earthquake. For further explanation of how earthquakes occur, see this excellent animation from the BBC.

Measuring Earthquakes

We measure the magnitude (strength) of an earthquake using a seisometer, the results of which are recorded on a seismograph. To see how a seismograph works, watch this excellent animation. The magnitude of the earthquake, reflecting the energy released, is measured on the Richter Scale (from 1-10). This is a logarithmic scale and therefore each point on the scale is 10x greater than the previous one. Therefore an earthquake measuring 8 on the richter scale is 10 times more powerful than an earthquake measuring 7 on the richter scale.

The Effects of Earthquakes

The effects of earthquakes are far ranging and often involve death and destruction. In 1906, a particularly large earthquake, measuring 8.2 on the Richter scale hit San Francisco (California, USA). Whilst at the time around 500 deaths were actually reported, the actual figure is believed to be around 3,000, the largest death toll from a natural disaster to be recorded in California. Although the actual shaking of the ground during the earthquake was incredibly damaging, it is estimated (wikipedia source) that 90% of the destruction was caused by the severe fires (see photograph) which raged following the earthquake, many starting as a consequence of ruptured gas mains.

We can divide the effects of an earthquake into those known as the primary effects and those known as the secondary effects. Primary effects of an earthquake are those resulting directly from the earthquake itself. These include; buildings collapsing; roads cracking; bridges giving way; shattering of glass and injuries / deaths resulting from these. Secondary effects are those that result from the primary effects. For example ground shaking may result in the cracking of gas and water pipes (primary effects) this can result in severe fires due to explosion from escaping gas and difficulties in putting out fires due to lack of water from burst mains (secondary effects). Other secondary effects include, homelessness, business going bankrupt and closing etc.

You need to learn a case study of the causes and consequence of a major earthquake - see post on the 1989 San Francisco earthquake.

Follow up links:
USGS - The Richter Magnitude Scale
National Earthquake Information Centre
Earthquakes - General interest publication from the USGS
Wikipedia - 1906 San Francisco Earthquake
Discover our Earth - Earthquakes
How earthquakes work
Understanding Earthquakes
Earthquakes do occur in Britain - see the British Geological Survey site Earthquakes in the British Isles
Map of recent earthquakes in the UK (BGS)
Earthquake Animation

Key Term Check:
Earthquake - a sudden ground movement
Epicentre - this is the point on the surface directly above the focus of the earthquake
Fault - a weakness in the earth's crust where an earthquake may occur
Focus - this is the point underground where the earthquake starts
Richter Scale - a logarithmic scale used to measure the magnitude of an earthquake
Seismic Waves - waves of energy released in the event of an earthquake
Seismograph - used to measure seismic waves released during an earthquake

Volcanoes - Prediction Technology and Satellite Imagery

2007-01-14T04:32:00.001-08:00

Advances in science and monitoring techniques have meant that scientists have made great advances in forecasting eruptions. A number of different techniques are used to monitor changes in physical processes which may indicate increasing volcanic activity. However, due to the availability of expertise, cash and technology, only 20% of volcanoes are currently monitored, most of which are in MEDCs.

Prediction / Monitoring Techniques:

Remote Sensing
Landsat images which show the amount of energy from the sun being reflected from the earth's suface when an image is taken by a satellite, can be used to indicate environmental change and can be used to identify areas affected by an eruption. This can then be used for future hazard mapping (see below).

Other satellite imagery can be used to predict volcanic eruptions. Infra-red images of volcanoes can be made every 15 minutes by geo-stationary satellites allowing thermal mapping to be used to detect hot spots where magma is rising to the surface, enabling a warning to be given. In 1998, the eruption of Pacya in Guatemala was detected a week before it happened by a satellite using infra-red detectors. A heat signal was picked up indicating hot magma rising to the surface. Success in predicting eruptions in this way has been experienced in other areas as well. However, in some areas the sheer number of volcanoes combined with the poverty of the area means the technique is less useful. Where it can be used, it can however provide valauble hours or even days in which to evacuate people from areas facing an impending eruption.

See also the USGS overview of Remote Sensing for Monitoring Volcanoes

Seismicity
Earthquake activity can often increase prior to a volcano as magma and gas rises. The rising magma and gas can cause vibrations and trigger earthquakes. Scientists monitoring seismicity (earthquakes activity) in volcanic areas can detect an increase in earthquakes and the type and intensity of the activity can be used to determine when an eruption is occuring. For further information see the USGS overview of Monitoring Volcano Seismicity

Ground Deformation

As magma rises it can cause a change in the shape of a volcano. Changes in the ground may include subsidence, tilting, or even the formation of a bulge when the magma rises. Remember, during the lead up to the eruption of Mt St Helens a cryptodome formed on its side due to the rising magma. Tilt metres, surveying techniuqes and even satellite imagery can all be used to detect and monitor ground deformation. For more information on the techniuqes used, see the USGS overview of Monitoring Volcano Ground Deformation

Volcanic Gases

The build up of gases are one of the driving forces of volcanic eruptions and monitoring gases such as sulphur dioxide can be important in the prediction / monitoring of volcanic activity. An increase in sulphur dioxide emissions can reflect rising magma. Likewise, a sudden decline in sulphur dioxide emissions following a period of rapid increase can suggest some blockage which may result in the build up of pressure prior to eruption. For more information on the measuring of gas emissions, see the USGS overivew of Monitoring Volcanic Gases

Hazard Assessment

Hazard Mapping

Being prepared for volcanic events can ensure the saving of many lives through successful evacuation. As well as careful monitoring of volcanoes and the implementation of carefully thought out evacuation plans, hazard mapping can help to determine the areas most at risk from an eruption by taking into account the behaviour and hazards associated with previous eruptions in order to help determine which areas most at risk and thus to determine evacuation zones.

This is an example of a Hazard Zonation map for Mount St Helens - it comes from the USGS's report on Volcanic-Hazard Zonation for Mount St Helens, Washington, 1995 (USGS) - the report considers areas that are most likely to be at risk (known as hazard zones) during future eruptions. The zonation takes into account experience during previous major eruptions such as the 1980 eruption as well as monitoring of changes in the volcanoes hydrology, topography and geology.

See USGS - Volcano Hazard-Assessment Techniques.

Research into volcanic risk and hazard management can help in a number of ways, but the messages don't always work, for example due to distrust in information sources or public apathy resulting from long periods of inactivity by some volcanoes. This poster explores the dangers of volcanoes, why lives are still lost, how research can help and why messages of warning / prediction don't always work.

Follow Up Links:
Wikipedia - Volcano Prediction - a comprehensive account of general principles and methods of volcano prediction / monitoring
Discovery Channel - Monitoring and Predicting Volcanoes
USGS Cascades Volcano Observatory - Volcano Monitoring Overview
Deadly Shadow of Vesuvius - Can we predit Eruptions?
Prediction of Danger - methods and instructments of monitoring
Volcanoes - Can we predict Volcanic eruptions?
Volcano Monitoring Techniques
USGS Overview - Volcano-Monitoring Techniques

Key Term Check:
Remote Sensing - the use of satellite imagery to detect clues of volcanic activity which are beyond the normal range of human revision, using ultra-violet, infra-red and microwave sensors. As well as tracking eruption clouds, thermal-sensing can be used to detect hot features on volcanoes which can indicate areas where magma is rising closer to the surface.
Ground Deformation - this refers to changes in the slope / shape of a volcano which can indicate the rising / build of magma. (think about the cryptodome which grew on the North flank of Mount St Helens prior to its eruption in 1980)
Hazard Mapping - a technique used to map out areas most at risk during future eruptions and the likely hazards (this mapping is based on experiences during past eruptions)
Seismicity - this simply refers to earthquake activity (which frequently preceeds / accompanies volcanic eruptions).

Photo courtesy of USGS

Living with Volcanoes

2007-01-14T04:31:00.001-08:00

Despite the well known hazards associated with volcanic eruptions, it is estimated that 360 million people still live in volcanically active areas. So why do people still live near volcanoes?

Reason: Fertile Soils
Explanation: Volcanic soils are some of the most fertile in the world due to the weathering of volcanic products such as ash lava and rock, which release valuable nutrients and minerals which enrich the soil as well as improving soil characteristics such as moisture retention. In tropical areas in particular, for example Hawaii, climate conditions mean that the weathering of lava etc. is fairly quick resulting in the growth of lush vegetation due to the rapid soil formation. As volcanic areas are therefore ideal for growing crops, they attract large populations.
Example: In Java (Indonesia) some of the best rice growing areas are in the shadow of volcanoes such as Mt Merapi which attract large numbers due to the rich farming opportunities (1 million live within 20 miles of Merapi). Likewise, in Italy large numbers live on the slopes of Vesuvius and Etna (one in five Sicilians are belived to live on the slopes of Etna) due to the fertile soils which provide rich opportunities for growing products such as Olives and fruit.

Reason: Geothermal Energy
Explanation: Heat from magma sources close to the surface in volcanic areas can be used as a source of Geothermal energy which can be harnessed to produce electricity. In these instances, superheated steam, created by the heating of water in permeable rocks in magma can be used to drive turbines. This use of energy is renewable and sustainable, it has the added advantage of being pollution free.
Example: Over 20 countries around the world generate geothermal power, including the US, Italy, New Zealand and Iceland. In fact 17% of Iceland's electricity is created in this way.
In farming areas around Reykjavik (Iceland), geothermal energy is also used to heat greenhouses enabling the growing of fruit, vegetables and flowers.

Reason: Tourism
Explanation: Due to the spectacular scenery associated with volcanic landscapes and unique features such as lava flows and geyers, volcanoes, particularly those having experienced recent eruptive activity are particularly popular with tourists. This is a huge economic benefit due to the resulting multiplier effect. Tourism attracts curstom for businesses such as hotel, cafes etc. creating jobs and improving the local economy.
Example: Yellowstone National Park in the USA with the famous Old Faithful geyser receives around 3 million visitors a year. Iceland is famous for its volcanic landscpae and its hot springs and geysers have attracted many tourists. The Blue Lagoon, near Reykjavik is a spa popular with tourists for its known positive effectives on the skin.

Reason: Minerals
Explanation: Valuable minerals such as copper, gold, silver, lead, zinc and even diamonds are all associated with volanic regions as they are associated with the rising magma which may cool and harden beneath the volcano. As hot water circulate within the cooled magma, the metals are taken by the water and re-deposited in greater concentrations. Thus volcanic areas are excellent areas for mining creating economic activites through job opportunities and the value of the mined minerals.
Example: Copper, Gold and Silver mining began around Mount St Helens as early as 1892.

Reason: Apathy / Unwillingness to Leave Home
Explanation: Due to the infrequency of some volcanic eruptions, some people, particularly those who have not experienced a volcanic eruption in their lifetime are reluctant to leave their homes in order to move to safety and ignore warning, preferring to live with the threat of a volcanic eruption. Some believe that there will be time to move / be resuced should an eruption begin.
Example: Harry Truman was an 83 years old man who lived by Spirit Lake in the Shadow of Mount St Helens. He died in the 1980 eruption due to his failure to heed the warnings of the government and evacuate the area.

Reason: Lack of Choice
It should also be recognised that some people have no choice but to live in these areas. In areas of poverty, people do not have the resources available to move and for many farming on the fertile soils in the shadow of a volcano may be the only livelihood they know.

Follow up Links:
USGS - The "Plus Side" of Volcanoes
Geography Pages - Benefits of Living in Volcanic Areas (thanks to Alan Parkinson)

Photo Source: USGS

Volcano Case Study: Mount St Helens 1980

2007-01-07T04:18:00.003-08:00

Mount St Helens, Washington State, NW USA is located in the Cascade mountain range and prior to its eruption in 1980 it had been active for over 100 years. The volcano sits on a destructive boundary where the Juan de Fuca plate meets the North American plate.

Mount St Helens erupted on May 18th 1980 following a period of activity which began in March 1980 with an earthquake measuring 4.0 on the richter scale. What followed was 3 months of seismic activity as magma rose within the mountain. As the magma rose, a large bulge grew on the north flank of the volcano, this was due to a blockage in the main vent resulting in the growth of a cryptodome (mound of viscous lava) in the side of the volcano.

On May 18th, an earthquake measuring 5.1 on the richter scale caused a landslide on the northern flank of the volcano, which in turn exposed the cryptodome below, resulting in a sudden release of pressure and a cataclysmic eruption in the form of a lateral (sideways) blast. The blast zone consisted of 230 square miles with the eruption leaving a 'lunor' landscape in its wake.

Watch the short video clip below to remind yourself of the nature of the lateral blast:

The effects of the eruption included:
* laval flows and ash filling in Spirit Lake and log jams and ash blocking the channel of the Toutle River;
* 57 people died in the eruption - most from poisonous gases;
* large number of wildlife were killed by the blast and the volcanic ash with nothing surviving in the blast zone
* flooding resulting from blocked rivers washed away road and rail bridges
* crops were ruined and livelihoods of loggers were devastated with large areas of trees being flattened like matchsticks.

For your exam you will need to learn a detailed case study of a volcanic eruption, using Mount St Helens as your eruption. You will need to be able to discuss causes and effects of the eruption and the responses of people to the event. It is important that you learn some place specific detail / facts and figures to put into your exam answer in order to reach the highest marks.

CREATING YOUR CASE STUDY
Through the use of class notes and independent research you now need to create your case study. You task is set out below and there are a number of links for you to follow up for further information.

TASK: Your task is to write an article for a magazine. You should give your work the title "Volcanic Fury - the 1980 eruption of Mount St Helens" and you need to ensure that you include labelled diagrams / pictures in your work. You need to ensure that you structure your work using the sub-heading given on the task sheet (which can be downloaded here).

The following websites should provide useful information and photographs to help you, but you should also make good use of your video notes and information from classwork.

USGS Background Information on Mt St Helens
Mount St Helens National Volcanic Monument - includes tourist information related to Mount St Helens and a useful digital library with pre and post eruption images (useful for comparions / exploring effects).
Global Volcanism Programme - St Helens (basic facts)
Wikipedia - 1980 eruption of Mount St Helens - includes some very useful information on aftermath, including impacts such as cost etc. and a good overview of the build up to disaster - worth exploring!
Mount St Helens - from the 1980 eruption to 2000 (USGS)
Vegetation around the volcano - before and after (comparative photographs)

To view Mount St Helens in Google Earth download this .kmz file (you will need Google Earth on your computer to be able to view this).

See this fantastic panorama from the top of Mount St Helens after the eruption.

Photograph courtesy of the USGS

Volcanoes

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Volcanoes are simply vents at the earth's surface through which lava and other volcanic products are erupted. Although many volcanoes are cone-shaped, different types of volcano exist according to their location and the products they are made up of.

The distribution of volcanoes
Volcanoes occur in narrow, linear belts and are mostly found along destructive boundaries with large numbers found around the Pacific Ring of Fire (the area marking the boundary of the Pacific plate). They are also found at constructive plate margins such as the Mid-Atlantic Ridge. An exception to the general distribution of volcanoes is those found in the middle of the Pacific Plate (the Hawiian islands) which are formed due to hotspot activity.

As well as describing the distribution of volcanoes you will need to be able to describe and explain their occurence at plate boundaries:

Volcanoes at Destructive Boundaries:
1. Plates move together due to convection currents
2. Heavier oceanic plate is subduced
3. Friction between the plates and heat from the interior causes the subducting plate to met
4. Melting of the plate creates molten magma
5. This magma is less dense than its surrounding and therefore rises and is erupted at the surface through a weakness in the crust creating a volcano.
6. Volcanoes at Destructive boundaries tend to be quite explosive due to the build up of pressure and gases.

Volcanoes at Constructive Boundaries:
1. Plates move away from each other due to convection currents
2. This creates a weakness / 'gap' in the crust
3. Magma is a able to rise to plug the gap forming lava flows and submarine volcanoes
4. As magma continues to build up above the surface of the ocean, volcanic islands (such as Surtsey) may form.
5. Eruptions at constructive boundaries tend to be gentle with little pressure build up

Volcanoes at Hotspots:
As mentioned in the last post, volcanoes may also be created at Hotspots - for example the Hawaiian Islands (with volcanoes such as Kilauea). See this animation as a reminder of how hotspot activity can result in the formation of volcanoes.

Structure of a Volcano:

Some Volcanic eruptions are more explosive than others due to the type of magma. At destructive margins andesitic magma gives rise to acid lava which is thick and sticky. As gases can't escape easily pressure builds up resulting in violent explosions.

In contrast at constructive margins, basaltic lava gives rise to basic lava which is thin and runny and from which gases escape easily. These eruptions are therefore more gentle in nature and less explosive.

Follow up Links:
Some great images and information on individual volcanoes at Volcano World
Animation - eruption of a stratovolcano (Savage Earth)
Volcanoes Online - a detailed source of information on types of volcanoes

Key Term Check:
Volcano - a vent on the earth's surface through which lava erupts
Hotspot - a thermal plume of magma which rises underneath a tectonic plate
Magma Chamber - an underground chamber storing molten rock
Secondary Crater - a small crater often cut into the side of a large cone (may form due to a blockage in the main cone)
Crater - a large opening at the top of a volcano from which gases, lava and ash etc. escape
Vent - pipe taking magma towards the main crater
Pyroclastic Flow - a cloud of burning ash, gases and other volcanic material which can travel downslope at great speeds.
Volcanic Bombs - large, hot boulders ejected during an eruption
Magma - molten rock under the ground
Lava - molten rock which reaches the ground surface

The photographs in this post are courtesy of the USGS

Plate Boundaries

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Plate Boundaries

The point at which two tectonic plates meet is called a plate boundary. It is at these locations where tectonic activity results in earthquakes, volcanoes and the formation of mountain ranges due to the movement of the plates. The diagram below shows the major plates and their boundaries. The arrows indicate the direction of movement at each plate. It is the direction of movement as well as the difference in crust which determine the variations in processes and landforms at the different plate boundaries. (animation from USGS)

There are a number of different types of plate boundaries. For each plate boundary you will need to be able to describe (i) the movement (ii) processes which occur and (iii) an example

1. DESTRUCTIVE BOUNDARY (also known as a convergent boundary)
Movement: Two plates moving towards each other (continental and oceanic crust)
(note where two oceanic plates meet one will be subducted and an island arc will form)

Processes: The denser oceanic crust is subducted underneath the continental crust forming a subduction zone and oceanic trench. As it is subducted it melts due to heat and pressure. The heat sources are friction between the two plates and from the earth's interior. Melting of the subducting plates creates magma which is lighter than the mantle and therefore rises resulting in the formation of volcanoes. Earthquakes also occur at this type of boundary due to the friction and pressure during subduction.

Landforms Created: Fold Mountains and Ocean Trench

Example: South American and Nazca Plates (forming the Andes and a deep sea trench (Peru-Chile trench))

Animation: click here to see an animation of the processes at a destructive plate boundary (with thanks to Wycombe High School)

2. CONSTRUCTIVE BOUNDARY (also known as a divergent boundary)
Movement: two plates moving away from each other (see animation opposite - courtesy of USGS)

Processes: As the two plates separate, hot magma is able to rise to fill the 'gap' creating new crust. As magma continues to build up, new mountain ranges form under the sea creating a mid-oceanic ridge. Where rising magma continues to build up above the ocean surface, a volcanic island is formed (for example Surtsey, Iceland). Both earthquakes and volcanoes occur at this type of boundary.

Landforms Created: Ocean Ridge; Volcanic Islands

Example: North American and Eurasian Plate - (forming the Mid-Atlantic Ridge)

Animation: click here to see an animation of the processes at a constructive plate boundary

3. COLLISION BOUNDARY
Movement: two plates moving towards each other (both continental crust)

Processes: As both plates consist of continental crust they both resist subduction and buckle and fold, being forced upwards to create fold mountains, such as the Himalayas. Although there is no volcanic activity at these locations, due to the forces of collision major earthquakes often occur here.

Example: Indo-Australian and Eurasian Plate (forming the Himalayas)
Animation: Click here to see an animation of the processes at a collision boundary

4. CONSERVATIVE BOUNDARY
Movement: two plates moving alongside each other

Processes: crust is neither created or destroyed here but as both pressure and friction results during the movement of the plates side by side, a 'stick-slip' motion results in the creation of significant earthquakes. Pressures builds up due to friction between the plates and when the plates break apart the energy is sent through the earth as seismic waves in the form of an earthquake.

Example: San Andreas Fault - North American and Pacific Plates

Animation: See this BBC visualisation of the San Andreas Fault conservative boundary

HOTSPOTS
You should be aware that whilst most volcanoes / earthquakes occur along plate boundaries, there are exceptions. For example the volcanic Hawaiian islands which can be found in the middle of the Pacific Plate are formed due to a Hotspot. Hotspots are plumes of molten rock which rise underneath a plate causing localised melting and the creation of magma resulting in volcanic activity. See this animation for further explanation of hotspot activity.

Follow up Links
An excellent site from the USGS called "Understanding Plate Motions" provides further information
A Flash animation showing the major plate boundaries.
Plate Tectonics on Wikipedia also provides a good overview of the processes at plate boundaries

Key Term Check
Constructive Boundary (Divergent) - where two plates move away from each other resulting in new crust being formed.
Destructive Boundary (Convergent) - where two plates move towards each other - in the case of a plate consisting of continental crust meeting a plate consisting of oceanic crust, the oceanic crust will be subducted and destroyed as it is less dense.
Conservative Boundary - where two plates move alongside each other - although crust is neither created or destroyed here, earthquakes usually occur here.
Collision Boundary - where two plates of continental crust move towards each other creating fold mountains.
Volcano - a vent through which lava, ash etc. is erupted (often, but not always cone-shaped)
Earthquake - a sudden ground movement

Plates and Convection Currents

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Plates and Types of Crust
The earth's crust is divided up into a series of slabs of crusts known as plates. These plates consist of two different types of crust: continental crust and oceanic crust. There are important differences between the two types. Oceanic crust is constantly being created and destroyed, it is therefore younger than continental crust and its higher density means that it can be subducted and destroyed. As continental crust is ligher with a lower average density, it is permanent and cannot sink. It is also much older and thicker, reaching up to 70km under mountains. In terms of rock type, continental crust is mainly granite, whereas oceanic crust is mainly made up of basalt.

Plate Movements and Convection Currents
The earth's tectonic plates are in motion, moving like giant 'rafts' on top of the semi-molten mantle below. However this movement is slow and rates vary from less than 2.5cm /yr to over 15cm/yr.

The movement of the earth's crustal plates is believed to be due to convection currents which occur in the semi-molten mantle. These convection currents are created by heat from within the earth - much of which is generated by radioactive decay in the core.

So how do convection currents cause plate movements? As semi-molten rock in the mantle is heated it becomes less dense than its surroundings and rises. As it reaches the crust above, it spreads out carrying the plates above with it. As the semi-molten rock then cools, it gradually sinks back down to be re-heated. (see diagram above)

Follow up links:
The Earth's Crust in Motion - an excellent page from St Vincent's College - exploring the nature of the crust and its movement due to convection currents - well worth a read!
A simple animation of convection and the resulting movement of plates
A clear and detailed animation of convection currents in the mantle
An animation of convection in the mantle (Exploring Earth)
The Mantle A good overview of the characteristics and influence of the mantle in tectonics

Key terms check:
Tectonic plate - individual slab of the earth's crust
Convection Current - transfer of heat throughout the mantle resulting in the rising and falling motion of semi-molten rock
Mantle - the area between the crust and the earth's core the majority of which is in a semi-molten state

Plate Tectonics: An Introduction

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Continental Drift and the Structure of the Earth

Image courtesy of USGS

Our next unit is the study of plate tectonics. In this unit we will be studying the forces of nature which have shaped our planet including the processes behind natural hazards such as earthquakes and volcanoes. We will also be considering the impact that such hazards have on people across the world. It is believed that out continents have not always been in their present configuration and that over millions of years our continents have changed their position (see animation). This theory is known as continental drift.

Millions of years ago there was one supercontinent called Pangea. Over time this has split into smaller continents which have gradually moved into the positions in which they exist today. There are various pieces of evidence for this including the apparent jigsaw fit between the east coast of South America and the west coast of Africa.

In order to understand how this is possible we need to consider the structure of the earth.

The earth is up to 6,000km in radius from the inner core to the surface. It is made up of four main layers. The surface layer is known as the crust. This is the relatively thin layer on which we live and it consists of solid rock. The crust 'floats' on top of the mantle. The mantle has very high temperatures resulting in rock being in a 'molten' state. This 'molten' rock is known as magma and is able to move. At the centre of the earth is the core. This is divided into the outer and the inner core. The outer core is partly molten whilst the inner core is solid, this is due to the extreme temperature and pressures which exist here, with temperatures reaching up to 5,000 oC.

Follow up Links:
Some useful and clear animations showing the movement of the continents over millions of years in the process of continental drift can be found here:

- Continental Drift

- The 'fit of the continents' (evidence for continents having moved)

- Sea floor spreading showing the break up of Pangea

Check out this excellent site for more information about the structure of the earth and its layers. Further detail on the structure can be found here.

Key Terms Check:

Continental Drift - the theory that our continents have changed their postion over time
Crust - the outer layer of the earth (up to 75km thick)
Mantle - the middle and thickest layer of the earth part of which is semi-molten in nature
Outer Core - the outer layer of the core is semi-molten
Inner Core - central part of the earth which is solid due to extreme temperature and pressure
Magma - molten rock in the mantle