Managing Earthquakes and Volcanoes

Use this PowerPoint in conjunction with your books to help you revise

What do you need to revise?

• Where earthquakes and volcanoes are found• Structure of the earth• How plates move (convection currents)• Plate boundaries (constructive, destructive, conservative)• Mt St Helen’s volcanic eruption: causes and impacts (on

people and environment)• Kashmir and Los Angeles earthquakes: impacts explained

(think about the difference between rich and poor countries)

• Reasons why people live near volcanoes

Where are earthquakes and volcanoes found?

• Earthquake and volcanoes are found near/on plate boundaries

Structure of the Earth

Plate boundaries

Plates meet in three ways:• By moving apart (constructive)• By moving together (destructive/collision)• By moving past each other (conservative)

Kung Fu plate Boundaries video

Plate boundary Diagram Explanation

Constructive Two plates move apart and magma rises up to fill the gap. This forms new crust and create volcanoes. Earthquakes can also happen as friction builds up when the crust moves over the mantle.

Destructive An oceanic and a continental plate move together and the heavier oceanic crust is forced/subducts under the continental plate. The oceanic crust melts and creates new magma which then rises up through the continental crust to form a volcano. Earthquakes also happen here as friction builds up when the two plates move past each other.

Collision Two continental plates move together. Neither can sink so both are forced upwards to form mountains.

Conservative Two plates are sliding past each other (in opposite or the same direction) but at different speeds. This causes friction to then build up which is eventually released as an earthquake. No volcanoes happen here.

Mt St Helens

Mt St Helen’s song

Kashmir/Los Angeles EarthquakeHow does being in a rich or poor country affect what the effects of an earthquake will be?

Why do people live near volcanoes and earthquakes?

Reasons

Tourism

Geothermal energyFertile soils

Too poor to move

Family links/tradition

Mining

Sacred placeDon’t care