Earthquakes

• An earthquake is a sudden shake in the Earth due to the movement of the Earth’s crust.
• Seismologists are scientists who study earthquakes.
• The focus is the place where an earthquake begins beneath the earth surface.
• Epicentre is the point directly above the focus where the earthquake is at its strongest.
• Shock waves are waves that spread out in circles from the focus.
• A fault is a crack in the Earth’s crust.
• Earthquakes occur where two plates meet (sometimes this is at a fault) and the two plates are sliding in the same direction, one at a faster pace that the other. They become locked together and eventually one will jolt forward causing an earthquake.
• Tsunamis are underwater earthquakes.

  
• Earthquake features

  
• A seismograph is used to record an earthquake and how long it lasted.
• The Richter Scale was the original scale used to measure earthquakes, going from 1-8. However, this was replaced by the MMS (moment magnitude scale) to get a more reliable result for larger earthquakes and it goes from 1-10.