What are surface waves?

Surface waves are like ripples on the surface of a pond when you throw a rock into it.

Imagine you're at the beach, and you drop a pebble into a calm pool of water. The water around the pebble starts to move in waves, going out from where the pebble landed. These are surface waves, they only move on the top part of the water, not all the way down to the bottom.

Surface waves work like a chain reaction. When you drop the pebble, it pushes the water next to it, and that water pushes the water after it, like people in a line all leaning forward and backward at the same time. The wave moves across the surface, but the water itself doesn’t go very far, it just goes up and down.

You can see surface waves in action when you're having fun in the bathtub or watching rain fall into a puddle. Each drop makes its own little surface wave, and they all spread out, like invisible ripples you can feel if you put your hand in the water.