The Layers of the Earth

The Earth is more than a giant ball made up of dirt, rocks, and minerals. The Earth may look like a giant ball from when looking at it from the moon, and the surface may be water, dirt, and other minerals, but deep inside the Earth there are four main layers. These four layers of the Earth include the crust, mantle, outer core, and inner core.

The first layer most people are quite familiar with because they walk on it every day, or maybe even dig holes into it. It is called the Earth's crust. The Earth's crust is the outer layer of the Earth and is about 5 to 25 miles thick depending on its location. It is the thinnest layer, only about 3-5 miles thick under the oceans which is called the oceanic crust. Under the continents it is about 25 miles thick, which is called the continental crust. The temperatures of the Earth's crust can be anywhere between air temperature and 1600° F, which is hot enough to melt the rocks inside the Earth.

The thin layer of the crust is also broken into pieces called plates. The plates float on top of soft mantle below the crust. The movement of these plates can cause earthquakes to occur.

Two other areas of the Earth's layers are a part of the next layer, the mantle, and a part of the crust. They are called the lithosphere and the asthenosphere. The asthenosphere and lithosphere are mostly made up of rock types called granite and basalt.

The second main layer of the Earth is called the mantle. The mantle of the Earth is the largest layer and is about 1800 miles thick. It is made up of extremely hot, dense rock and it flows like asphalt. The temperature at the top of the mantle is about 1600° F and at the bottom it is about 4000° F. Basically, the mantle is made up of melted rock which allows the plates of the Earth's crust to float on top of it. When the melted rock escapes to the Earth's surface, a volcano may erupt in that area of the Earth. There are certain areas of the world where this is more likely to happen.

The final two layers of the Earth include the outer core and the inner core. The outer core is basically made up of melted metals, nickel and iron. Because these metals are melted, they move just like a liquid. The outer core is located about 1800 miles below the Earth's surface and is about 1400 miles thick. The outer core has temperatures between 4000° F and 9000° F.

The inner core is about 800 miles thick and the temperatures may be as high as 9000° F. There is so much pressure at this layer, the metals are squeezed tightly together and they are forced to vibrate as solids. The weight of the other layers of the Earth is basically pressing down onto the inner core of the Earth.

In summary, the four main layers of the Earth include the crust, mantle, inner core, and outer core. Two additional areas located between the crust and mantle are the lithosphere and the asthenosphere. Earthquakes are caused by the movement of the pieces of the Earth's crust called plates, and when a volcano erupts the melted rock comes from the mantle of the Earth. Finally, the inner and outer core are the hottest and deepest of the layers and are under the most pressure.