Question

What can tsunamis be directly caused by?

Answer 1

Several Reasons can trigger Tsunami or anything which causes vertical displacement of sea water. But Tsunamis due to earthquakes in Sea floor are most Common.

Explanation:

Reason Which can cause Tsunami
1. Massive Landslides In Ocean
2.Extraterrestrial Impact (meteoric impact)
3. Volcanic explosion in ocean
4. Volcanic dome collapse and fall in sea

Major Reason
Earthqaukes are the most common reason triggering tsunamis. Generally a magnitude of earthquake greater than 7.5 is believed to trigger tsunami. hope this helps thanks