Focus - the place where earthquakes begin, deep within the earth's crust.
Epicentre - the point above the focus where the earthquake is most strongly felt.
Shock waves - waves from the earthquake that radiate from the epicentre.
Primary waves - weak waves that cause the surface to move in the direction of the wave movement.
Secondary waves - stronger waves that warn of worse to come.
The richter scale - measures the magnitude (strength) of earthquakes. (1-10)
The Mercalli scale - measures the shaking and damage (intensity). (1-12).
Ground shaking - The longer the shaking the more damage is caused.
Landslides - slopes are weakened by strong shaking and give way.
Tsunamis - result when earthquakes occur under the sea.
Liquefaction - Groundwater rises to the surface, turning soft ground to mud.