explain how an earthquake causes a tsunami
Tsunamis are most often caused when an earthquake causes the seafloor to rise or fall. Earthquakes happen when two tectonics plates collide into each other at a plate boundary. The denser plate is subducted under the other plate, which leads to a rise or fall of the seafloor. This movement of the seafloor will cause a rapid vertical displacement of water, and waves of a tsunami would form. As the wave approaches the coastline, it would get higher as the seafloor gets shallower, causing a tsunami to become visible and then grow even higher as the water gets more shallow. The shock waves produced by the earthquake would radiate out and cause other waves to form too.