Geography GCSE Restless Earth Notes

The Structure of the Earth   The Core – made of solid iron and nickel The Mantle – semi-molten rock that moves very slowly causing the plates above to move The crust – split in to tectonic plates (continental and oceanic) and is only 20km thick Continental crust – thicker and less dense Oceanic crust – thinner and denser Plate margins/boundaries – where the plates meet     Plate Margins Destructive Plate Margin – for example: East coast of Japan. When oceanic plate meets continental plate the oceanic crust is forced down into the mantle because it is denser. Here it is melted and destroyed. This often creates volcanoes and ocean trenches. When two continental plates meet they smash together but no crust is destroyed.  Constructive Plate Margin – for example: Mid-Atlantic ridge. When two plates move away from each other, magma rises from the mantle to fill the gap. When it cools new crust is made.   Conservative Plate Margin – for example: San Andreas fault on the West Coast of the USA. Where two plates move sideways past each other or in the same direction but at different speeds often resulting in earthquakes.    Fold Mountains  Fold mountains (for example: the Himalayas, The Andes and The Alps) are formed at destructive plate margins. When tectonic plates collide, sedimentary rocks that have built up between them are folded and forced upwards to form mountains. Fold mountains can be formed where a continental plate and an oceanic plate collide, for example: The Andes in South America.  Fold mountains can also be formed where two continental plates collide, for example: The Himalayas in Asia and The Alps in Europe.   Case Study – The Alps The Alps are a fold mountain range located in Central Europe. They stretch across Austria, France, Germany, Italy, Liechtenstein, Slovenia and Switzerland. The Alps were formed approximately 30 million years ago by a collision between the African and European plates. The Alps have a population of about 12 million people and they are a popular holiday destination. The tallest peak is Mont Blanc (4810m) that lies on the Italian-French border.     Farming The steep upland areas are used to farm goats for milk, cheese and meat. Some sunnier slopes (such as Lavaux, Switzerland) have been terraced to plant vineyards. Hydro-electric power (HEP) The narrow valleys are dammed to generate HEP, for example: the Berne area, Switzerland. Switzerland gets 60% of its electricity from the Alps. The electricity is uses locally to power homes and businesses. Some is exported to towns and cities further away. Mining   Salt, iron ore, gold, silver and copper have been mined in the Alps but due to cheaper foreign sources the industry has declined. Forestry   Scots Pine is planted in the Alps because it is more resilient against munching goats that kill native tree saplings. The trees are logged and sold for furniture. Tourism   The Alps are a popular holiday destination with 100million tourists visiting each year. Most…