What causes tsunamis and how do they generate such destructive power?

A tsunami is like when a giant wave is created by something very big moving suddenly underwater, and it can knock everything down on its path.

Imagine you're in a bathtub filled with water. If you jump in all at once, the water splashes up and out, that’s like a tsunami. Now imagine instead of you jumping in, a mountain moves really fast under the ocean, boom! That creates a huge wave.

A tsunami usually starts when an earthquake happens on the ocean floor. The ground shifts suddenly, pushing up or pulling down part of the seabed. This movement makes the water above it go crazy, like when you push your hand under water in a bowl and make ripples.

Tsunamis travel across the ocean very fast, like a race car on water! When they reach the shore, they don’t look big at first, but then whoosh! The water piles up and crashes onto land, knocking everything in its path, just like when you pour a whole bucket of water over your toys. That’s why tsunamis can be so destructive.