As a result of the severe earthquake is a 8.0 and above on the Richter scale. The earthquake epicenter was under the ocean floor. Or near the coast In geology, we know that. Crust made up of plates (tectonic plates) are connected to each plate. When the plates move toward each other. Or separated to cause the earthquake. The intensity of the vibrations of the earth's crust is very little different each time. The area is along the boundaries of tectonic plates, earthquakes often occur more frequently. especially On the edges of tectonic plates, one plate slid beneath the submerged edges of the plates to another disc. It causes severe earthquake If the area beneath the sea. It caused a tsunami up.