Caption: This map from the U.S. Geological Survey shows earthquakes and volcanoes, represented by dots. Together, the dots show the boundary lines of the Earth's tectonic plates.
You may already know that the Earth has three main layers. We live on the crust of the Earth. The crust is the outermost layer. Even the oceans have a layer of crust under them.
Under the crust is the mantle. The mantle is made up of rock. It is not solid rock though. Inside the earth it is hot-hot enough to melt rock! The mantle is soft and fluid. It flows like melted plastic.
Under the mantle is the Earth's core. The core is very hot!