ELI5: What actually makes the ground shake during an earthquake?

Imagine you have a rug on the floor. Sometimes, you want to move it a little bit, so you push it.

Now, imagine the Earth is like that rug, but much, much bigger! And instead of you pushing it, the Earth's crust (the top layer, like the rug's surface) is broken into big pieces called plates. These plates are always moving, very slowly. Think of them like giant, puzzle pieces floating on something gooey underneath.

Sometimes these plates get stuck! They push against each other, building up a lot of energy. Imagine trying to push that rug when it's stuck under a heavy table. You keep pushing, pushing, pushing, and eventually, something has to give!

When the plates finally slip, all that built-up energy is released very quickly. It's like letting go of a stretched rubber band - it snaps back!

This sudden release sends out seismic waves - like ripples in a pond, or vibrations through the rug when you finally get it unstuck. These waves travel through the ground.

• When these waves reach your house, they make the ground underneath shake!
• The stronger the waves, the bigger the shake.