Kids Ask an Expert - How do earthquakes cause tsunamis?

Earthquakes can cause tsunamis when the ground under the ocean suddenly moves and pushes water up like a wave.

Imagine you're playing in a bathtub with your toys. When you jump into the tub, all that water gets pushed up and makes a big splash, that’s like what happens during an earthquake underwater.

Earthquakes happen when parts of the Earth move suddenly. If this movement is under the ocean, it can push a lot of water upward very quickly. This creates a giant wave called a tsunami.

Think of it like pushing a big pile of blocks, if you push them all at once, they fall fast and make a loud crash. Underwater earthquakes work in a similar way: the ground moves, and the water follows, creating waves that can travel across the ocean until they reach the shore.

When these tsunami waves get close to land, they grow taller, like when you put your hands together in front of a wave in the bathtub. That’s why tsunamis can flood coastal areas and cause big problems for people living near the sea.