natural hazard

natural disaster

earth

continental crust

plates move because mantle underneath moves with convection currents
where plates meet are called boundaries/plate margins

destructive plate boundary
no crust is destroyed
creates volcanoes

A constructive plate boundary, sometimes called a divergent plate margin, occurs when plates move apart. Volcanoes are formed as magma wells up to fill the gap, and eventually new crust is formed.

collision zone

A conservative plate boundary, sometimes called a transform plate margin, occurs where plates slide past each other in opposite directions, or in the same direction but at different speeds.

Friction is eventually overcome and the plates slip past in a sudden movement. The shockwaves created produce an earthquake.

types of plate boundary

destructive margins cause earthquakes

constructive margins cause earthquakes

conservative margins cause earthquakes

destructive margins cause volcanoes

constructive margins cause volcanoes

constructive margins cause volcanoes

earthquakes

volcanoes

focus

epicentre

seismometer

shockwave

richter scale

magnitude

magma chamber

lava

crater

vent

secondary cones

ash, steam and gas

volcanic bombs

composite volcanoes

shield volcanoes

primary impacts of earthquakes

secondary impacts of earthquakes

impacts of earthquakes are more severe in LEDCs

people live in earthquake prone areas

reduce impacts of earthquakes

earthquake in MEDC:
Italy 6th April 2009
6.3 on richter scale
destructive margin
damage $15 billion

earthquake in LEDC:
Pakistan 8th October 2005
7.6 on richter scale
destructive margin
damage $5 billion

lots of people live close to volcanoes

primary impacts of volcanoes

secondary impacts of volcanoes

reducing impacts of volcanoes