Course
Geography
GCSE
Modules (5)
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Where do volcanoes and earthquakes occur?
Crust is made of rock it is a solid and it is 8-65km thickMantle is made of rock the outer is solid and the inner is soft and it is 2900km thickCore is made of nickel and iron the outer is liquid 2220km thick and the outer is a solid which is 1260km thick
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Where do volcanoes and earthquakes occur?
Continental crust -Can't Sink-Could be made from Granite-Less dense-Older 1500 million years-Cannot be renewed or destroyedOceanic crust-Can sink-Could be made from igneous (basalt)-Denser-Newer 200 million years-Can be renewed and destroyed
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Where do volcanoes and earthquakes occur?
The crust is broken into plates-The lithosphere (crust and upper mantle) is broken into 14 major plates and 32 much smaller plates-Where these plates meet are known as plate marginsConvection currents in the mantle cause the plates to moveHot mantle is thought to rise, cool and sink again in a circular motion But some scientists have other theories-Slab-pull - the weight of the denser plate sinking into the mantle at ocean trenches. This pulls the rest of the plate along -ridge-pull - as oceanic ridges build up the weight of the ridge pushes the plates apart
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Types of plate margin
Destructive SubductionWhat happens:- Two plates move towards each other- Oceanic plate meets continental plate
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HIC Example of Tectonic Hazard NZ 2011
HIC example of Tectonic Hazards New Zealand 2011HIC = High Income CountryPrimary Effect = Caused by ground shaking and can include deaths and injuries, plus damage to propertySecondary Effect = Results of the primary effects and include tsunamis, fires and landslidesImmediate Response = the responses straight after for example search and rescue, medical care, food, water and immediate shelter