ELI5: Explain Like I'm 5

Synthetic seismogram

Imagine you have a toy car and you want to know how bumpy the road is ahead of it. You can place a tiny microphone on the car and listen to the sounds it makes as it rolls over the bumps. This is similar to how scientists use earthquake waves to learn about the Earth's interior.

A synthetic seismogram is like a pretend recording of what an earthquake wave might look like if it passed through the rocks below us. Scientists can use this pretend recording to learn about the Earth's interior without actually having to wait for an earthquake to happen.

To make a synthetic seismogram, scientists first create a computer model of the rocks and other materials that earthquakes travel through. They simulate an earthquake by making a "source," which is like someone shaking the ground in a certain way. This creates waves that bounce around inside the Earth's layers, just like sound waves from a car bouncing over bumps in the road.

The computer can then use algorithms to estimate what the earthquake waves will look like on the surface, thousands of miles away from where the quake actually happened. The scientists can look at this pretend recording (the synthetic seismogram) to figure out things like what the Earth's inner layers are made of or how they are shaped.

So, in simpler terms, a synthetic seismogram is like a scientist's make-believe recording of an earthquake that hasn't actually happened yet. They use it to learn about what the Earth is like inside without having to wait for an actual earthquake to happen.