Every country in the world sits on top of a large sheet of rock.
Earthquakes are caused by the movement of these sheets of rock and are measured on the Richter Scale.
Most earthquakes are just tremors which measure 3 or less on the Richter Scale.
But each year there are about eighteen earthquakes which measure between 7 and 7.9 .
These are many earthquakes.The earthquake that destroyed Kobe measured 7.2 on the Richter Scale.
the earthquake in Haiti measured 7 on the Richter Scale.
Geologists knew that two sheet of rock met and formed a sixty-five kilometre fault line near Port-au-Prince.
After the earthquake, they discovered that the two sheet of rock had moved nearly 2 metres in opposite directions against each other.