INTERNAL STRUCTURE OF EARTH

INTERNAL STRUCTURE OF EARTH

The Earth is composed of four different layers. The crust is the layer that you live on, and it is the most widely studied and understood. The mantle is much hotter and has the ability to flow. The outer core and inner core are even hotter with pressures so great you would be squeezed into a ball smaller than a marble if you were able to go to the center of the Earth!

The Crust

The Earth's Crust is like the skin of an apple. It is very thin in comparison to the other three layers. The crust is only about 3-5 miles (8 kilometers) thick under the oceans (oceanic crust) and about 25 miles (32 kilometers) thick under the continents (continental crust).

    The crust is composed of two rocks. The continental crust is mostly granite. The oceanic crust is basalt. Basalt is much denser than the granite. Because of this   the less dense continents ride on the   denser oceanic plates.

The Mantle

The Mantle is the largest layer of the Earth. The middle mantle is composed of very hot dense rock that flows like asphalt under a heavy weight. The movement of the middle mantle (asthenosphere) is the reason that the crustal plates of the Earth move.

The Outer Core

The core of the Earth is like a ball of very hot metals. The outer core  is so hot that the metals in it are all in the liquid state. The outer core is composed of the melted metals of nickel and iron.

The Inner Core

The inner core of the Earth has temperatures and pressures so great that the metals are squeezed together and are not able to move about like a liquid, but are forced to vibrate in place like a solid.

The Layers of the Earth