Final answer:
Tsunamis are caused by disturbances on the ocean floor, usually resulting from tectonic activity such as earthquakes or volcanic eruptions.
Step-by-step explanation:
Tsunamis are caused by disturbances on the ocean floor, usually resulting from tectonic activity such as earthquakes or volcanic eruptions. When these disturbances occur, they can generate powerful underwater waves that travel across the ocean and eventually reach the coastline, causing massive destruction. For example, the 2004 Indian Ocean tsunami was triggered by a massive earthquake beneath the ocean floor.
Learn more about causes of tsunamis