7) explain how tsunamis are formed. how do tsunamis change the surface of the earth?

A tsunami is a series of waves generated in an ocean or other body of water by a disturbance such as an earthquake, landslide, volcanic eruption, or meteorite impact. The picture at the left shows how an earthquake can generate a tsunami in the overlying water.

By washing away large surfaces of land and depositing it in a different area. Also does damage to structures and deposits salt into the soil.