Based on the records of the USGS, Indonesia has had more than 150 earthquakes with magnitude > 7 in the period 1901–2017.Where is a tsunami most likely to happen?
Tsunamis are most likely to occur in the Pacific and Indian Ocean regions. Tsunamis are most commonly formed from undersea earthquakes that result in a sudden rise or fall of the Earth's crust under the ocean.What is it about an earthquake that causes a tsunami?
Most tsunamis are caused by earthquakes generated in a subduction zone, an area where an oceanic plate is being forced down into the mantle by plate tectonic forces. The friction between the subducting plate and the overriding plate is enormous.