What causes seafloor displacement?

When something big moves under the ocean, it can push or pull the ground below the water, that's what causes seafloor displacement.

Imagine you're playing with a soft mattress on the floor. If you jump on one side of it, the other side goes up, that’s like how seafloor displacement works. The ocean floor is like that mattress, and something big under it, like a plate (a giant piece of Earth's crust) moving, can push or pull it.

The Earth’s surface is made of pieces called tectonic plates, just like a puzzle. Sometimes these pieces move apart, sometimes they crash together. When they move, they can lift up the seafloor or drop it down, that’s seafloor displacement in action.

Think about when you push your friend on a swing. The swing moves because of the force from your push. Similarly, the Earth's movement under the sea pushes or pulls the ocean floor, making waves, sometimes really big ones!