every country in the world siss on top of a large sheet of rock earthquakes are caused by the movement of these sheet of rock and are measured on the richter scale most earthquakes are just tremors which measure 3 or less on richter scale but is year there are about eighteen earthquakes which measured between 7 and 7.9. these are major earthquakes the earthquake that destroyed kobe measureed 7.2 on the richter scale the earthquake in haiti 7 on the richter scale geologists knew that to sheets on rock met and formed a sixty five kilometre fault line near port au prince after the earthquake they discovered that the two sheets of rock had moved nearly 2 metre in opposite directions against each other