Earthquakes

Earthquakes:

Earthquakes are vibration in the Earth's crust that are caused when tension is released at plate boundaries that have become 'struck'

Earthquake energy is released in seismic waves. Theses waves spread out from the focus. The waves are strongest at the epicentre, becoming less strong as they travel further away. 

The origin of the earthquake in the crust is called the focus. The point on the surface closest to the focus is called the epicentre

Earthquakes can occur at all plate boundaries, but are stronger at destructive and conservative plate boundaries

The power of an earthquake is measured using a seismometer. It detects the vibrations from the earthquake and plots it on a graph called a seismograph

The strength, or magnitude, of an earthquake is given using a richter scale, from 1 to 9. 1 to 2 earthquakes can occur everyday in some places like Japan, but are so small that people dot recognise them

Eathquakes at destructive plate boundaries: 1. Convection currernts inn the mantle cause tectonic plate to move towards each other. 2. The process subduction occurs, when a denser oceanic crust sinks under a lighter continental crust. 3. The plate get 'stuck' 4. A sudden release of this pressure allows the plates to jolt and move suddenly at the plate boundaries. These release seismic waves which are felt as earthquakes

Earthquakes at constructive plate boundaries: 1. convection currents in the mantle can cause tectonic plates to move away from each other. 2. As the plates move apart, stress builds up. 3.  Continued plate movement overcomes the stress and the plates move slightly causing weak earthquakes.

Earthquakes at conservative plate boundaries: 1. convection currents in the mantle cause plate boundaries to slide past each other horizontally. 2. The 2 plates 'stick'. 3. This causes pressure and stress to build up. 4. The release of pressure is quick and sudden, causing very large seismic waves which are felt as strong earthquakes. 

LEDCs suffer more from the effects of an earthquake than MEDCs. LEDCs are less able to predict earthquakes; they have less money, technology and knowledge to monitor earthquakes. LEDCs are less able to plan and…