The ground we walk on is only one level of the many-layered planet Earth. Each of the Earth's layers have different thicknesses and unique qualities.
The surface of Earth is called the crust and stretches four miles beneath the oceans and 22 miles beneath land. The crust is on top of the lithosphere, which lies on top of the mantle.
The mantle is the layer of solid and molten rock that makes up the greatest part of Earth’s mass. It also keeps most of the planet’s heat in. Cold, hard rock from the lithosphere sinks into the lower mantle's hot, molten rock surface. The molten rock then rises to the very top level of the Earth through the upper mantle, where it shoots out as lava. This process can take up to millions of years.
Earth's many layers facilitate a cycle in which heat rises and cold rock sinks. This cycle, powered by heat from the Sun, creates movement and change in the mantle.
There’s a lot going on beneath the surfaces we walk on. Who knew that there was magma right beneath our feet?
[Source: Kingfisher People Book of Planet Earth]