The Earth’s Layers Scientists have spent many years determining what is inside the earth. Geologists can’t use x-rays to see inside the earth or dig a hole deep enough to explore what is deep inside the Earth. They have used instruments to measure earthquake waves move through the Earth. These waves pass through different materials at different rates. By analyzing earthquake waves, geologists have theorized that the interior of the earth consists of layers.

Inside Our Earth Crust Mantle Outer Core Inner Core (10-25 miles) radius Inner Core Scientists have identified three main layers. At the center of the earth, is the core which is 750 miles in diameter. Next we find the outer core at 1,430 miles thick. Then we have the mantle at 1,800 miles. Finally, we have the earth’s crust which is very a thin layer in comparison to the rest of the earth at 10-25 miles. Inside Our Earth

Composition of the Earth’s Layers The crust is made of soil, water and rock. The mantle is hot part melted and part solid iron and magnesium. The outer core is made of hot liquid nickel and iron. The earth’s crust is composed of minerals. This is where we live and where the oceans and mountains are. Underneath the soil and water, is rock. Under the crust, is the mantle of the earth which is made of thick material. The mantle is made of hot, part melted, part solid rock. It is composed of iron and magnesium. This hot melted rock is so deep that we usually do not worry about it, however, sometimes it forces its way through the mantle to the surface of the earth as lava form a volcano. The outer core is composed of liquid nickel and iron, two metals that sank slowly through the mantle to collect at the center of the earth. The inner core is made of solid nickel and iron. Although it is hot enough to be a liquid, the pressure at the center of the earth squeezes metals into a solid. The inner core is made of solid nickel and iron. Composition of the Earth’s Layers