Very large earthquakes occur – for example, In Japan on 11 March 2011 when a mega-quake of Mw 9.0 sent a devastating tsunami over the coast The great earthquake came as a nasty surprise for Japan, which is otherwise very proven about the danger of earthquakes and tsunami, but which had not believed that they could be exposed to Such a big earthquake. But it is not always the greatest earthquakes that are the most devastating. In 2010, Haiti was hit by an earthquake of Mw 7.0, with great loss of life and great devastation. But there are 12-15 earthquakes of that size every year, and most often the damage is considerably less.