Restless Earth

Structure of the Earth:

• Crust - hard outer shell broken into tectonic plates
• Mantle - soft molten rock -  3800 degrees celsius
• Outer core - liquid iron and nickel
• Inner core - solid, cery hot, up to 5500 degrees celsius

Oceanic Crust

• 5-10km thick
• dense
• sinks into mantle when oceanic & continental plates meet
• oldest is only 180 million years old
• forms constantly at constructive plate margins 
• destroyed at destructive plate margins

Continental Crust

• 25-100km thick
• less dense
• doesn't sink
• very old - 3-4 billion years old
• new crust isn't formed
• can't be destroyed

Constructive Plate Boundary

• plates move apart
• magma rises to fill in the gaps
• cooled magma creates new crust
• earthquakes & volcanoes occur here
• Iceland, Eyafjallajokull - American & Eurasian plates

Destructive Plate Boundary

• two plates move towards each other
• oceanic plate meets continental plate
• oceanic sinks below continental (subduction) as it is denser
• this creates volcanoes and ocean trenches
• Earthquakes occur here
• Andes - Nazca & South American plate

Conservative Plate Boundary

• two plates move sideways past each other in opposite directions or the same direction at different speeds
• crust isn't created or destroyed
• earthquakes occur here
• California - North American & Pacific plate

Fold Mountains

• Form where plates collide at destructive margins
• when tectonics collide, sedimentary rocks fold and are forced up to form mountains
• fold mountain areas have high mountains which are rocky with steep slopes, snow & glaciers in the highest parts and lakes in valleys between mountains

Fold Mountains Case Study - Alps

• Located in central Europe - Switzerland, Italy, France, Germany, Slovenia, Austria, Liechetenstein
• Formed 30 million years ago when the European & African plates collided
• Tallest peak Mont Blanc - 4810m French-Italian border
• Population of 12 million

Farming:

• high mountain slopes aren't good for growing crops, so steeper areas are used to farm goats for milk & meat
• lower slopes are used for crops, or higher slopes are terraced
• some sunnier slops are used for vineyards - Lavaux, Switzerland

Tourism:

• 100 million tourists a year
• 70% of tourists in winter for skiing, snowboarding & ice climbing
• in summer people visit for mountain biking, hiking & paragliding
• new villages have been built to cater for the quantity of tourists - Tignes in France
• Ski runs, ski lifts, cable cars, holiday chalets & restaurants fill the landscape

Hydroelectric Power:

• narrow valleys are dammed to generate HEP - Berne, Switzerland
• 60% of Switzerland's electricity is from HEP in the alps
• electricity is used locally & exported

Mining:

• salt, iron ore, gold, silver & copper
• mining has declined dramatically because of cheaper foreign sources
• Mining is difficult in the Alps due to the steep slopes - zig-zag roads have been carved to get to them

Forestry:

• Scots Pine is planted over the Alps as it is more resilient to goats, who have killed native tree saplings
• Trees are logged & sold to make furniture, fuel & building materials

People have adapted to the conditions:

• Steep relief: goats are farmed as they are well adapted…