Tsunamis are large, powerful waves caused by the displacement of water in an ocean or large lake. They are sometimes referred to as tidal waves, although they have nothing to do with the tides. In most cases, they follow a mighty underwater earthquake, although other natural disasters like landslides can also spark these devastating surges. They are particularly insidious and terrifying because they are the unexpected disaster after the disaster. And while technology has advanced to help us better predict earthquakes and tsunamis, the safety measures in place still leave much to be desired, and it's often impossible to evacuate those in the line of danger in time.
Throughout history, hundreds of thousands of lives have been lost in the wake of tsunamis. Click through the following gallery to learn about some of the most devastating tsunamis ever to strike.