# What are the layers of the earth?

Dec 14, 2015

Crust, Mantle, Core (Outer and Inner)

#### Explanation:

Crust is the thinnest layer. Its thickness varies, for example the crust in ocean or oceanic crust has it thickness of only about $8$ $k m$ while in the continental crust it has a depth of up to $32$ $k m$. It is composed of O, Si, Al, Fe, Ca, Na, K, Mg, Ti, and H.

After that, there is a boundary discovered by Andrija Mohorovicic which is named after him. The Mohorovicic Discontinuity or sometimes known as the Moho.

The next one is the mantle which is about $2900$ $k m$ in depth. This makes up about 80 % of the Earth's volume and $68$ % of the its mass. It composed mainly of Si, O, Fe, and Mg.

The core:
Outer core which has a depth of $2250$ $k m$ is made of liquid Iron and Nickel. It surrounds the Inner core which has a radius of $1300$ $k m$. It is very dense. It is the innermost layer and is made of solid Iron and Nickel.