Answer:
About 100 earthquakes per year are strong enough to cause damage.
Most earthquakes are not strong enough to be felt by humans
Explanation:
Earthquakes happen very frequently because the earth’s tectonic plates are always on the move (though just a few inches per year) and they collide or brush against each other causing stress that is released regularly as earthquakes. Close to a million earth tremors that are undetectable to humans occur every year. These are 2.4 Ritcher and less in magnitude. However, every year there are about 100 earthquakes above 6.0 Ritcher in magnitude that cause damage.
