Geography revsion- Topic 5- Restless Earth

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  • Created by: Comfort
  • Created on: 24-04-13 14:14

Tectonic Plate-  a huge section of the Earth’s crust

There are TWO  main types of plates:

 

Continental Plate: (e.g. Eurasian Plate)

 

 Thick and less dense than Oceanic Plates

 Mostly Made of Granite

 They are those Situated underneath bodies of land (Continents)

 Very Old- 1,500 million years old

Oceanic Plates: (e.g. Pacific Plate)

1. Thinner and more dense than Continental plates

2. Mostly made of Basalt

3. Flat and are situated under large bodies of water e.g. Pacific Ocean

4. Younger than Continental Plates- 200 Million years old

 

What Causes Tectonic Movement?

 

Tectonic movement is caused by

Convection currents :

1. The radioactive decay that is happening in the core

heats up the mantle which rises as it is less dense.

2. The semi-molten rock spreads out and carries the plate

above with it.

3. This sideways motion moves the Crust’s Plates.

4. After movement, the mantle cools and sinks back

down to be reheated in the core.

The Three Different types of Plate Boundary:

 

1. The point at which plates meet is known as a Plate Boundary  

2. There are THREE  Types of Plate Boundaries:

Fold Mountain.

- Upland areas formed by the Buckling of the earth’s crust

They are found on destructive plate boundaries.

 

Formation of Fold Mountains:

 When Tectonic plates collide, the sedimentary rocks that have built up between them are folded.

 They are then forced upwards to form Fold Mountains.

Characteristics of Fold Mountain areas:

Fold Mountain areas have very high mountains with very steep slopes. (e.g. The

Matterhorn)

 At the highest/Coldest point, there is usually lots of snow.

 Many Glaciers are formed by erosion.

 Sometimes, lakes are found in the valleys between the mountains. (e.g. Lake

Geneva)

How are the Alps used?

Farming

: The steep upland areas are used for pastoral farming to graze goats e.c.t. and the sunnier south facing slopes have been terraced to plant vineyards. E.g. Lavaux, Spain

Hydro-Electric Power:

the narrow valleys are dammed to generate HEP. Switzerland receives 60 % of its power from HEP which is used in both housing and businesses.

Mining:

Sodium Chloride, Gold and silver are mined in the Alps, but in recent years mining has declined dramatically due to cheaper foreign sources.

Forestry:

Scots pine is planted all over the Alps because it is more resilient to the harsh winters. The trees are logged and sold to produce furniture.

Tourism:

- 100 million tourists visit the Alps each year making tourism a huge Source of its income.

- 70% of tourists visit the Alps for the steep snow covered mountains for recreational activities such as skiing and snowboarding. In the summer tourists come for Walking and climbing.

- Some villages have been built especially to cater for the vast amount of tourists. (e.g. Tignes, France)

- However, manmade eyesores like chair lifts have ruined the natural beauty of these areas.

How have the people living

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