September 4 2010 and Tuesday 22 February 2011 have been the scariest thing that anyone has ever been through in Christchurch. The earthquake and after shocks have happened due to earth movement.
Earthquakes are caused by two plates under ground coming together and crashing. Plates under ground can cause mountains to come up to the surface. Some earthquakes are caused by land moving along together and the land jams like a door. The land tries to break free but it can’t. Then all of a sudden the land breaks free and it causes the land to shake which makes an earthquake.