The Inner Core The deepest layer in Earth is the inner core. It is located at the center of the Earth because it contains the densest material of all of Earth’s layers. The inner core is solid and mostly composed of the element Iron (Fe). Its extremely hot temperature is estimated at 6,000 ⁰C. This layer is approximately 1,250 km thick.

The Outer Core The outer core is less dense than the inner core and, therefore, is located around the inner core. The temperature ranges from 4,000⁰C to 5,000⁰C. The outer core is approximately 2,200 km thick and is a combination of mostly molten iron (fe) and nickel (Ni). The outer core is Liquid.

The Mantle The mantle is located outside of the outer core. This layer is made mostly of iron (Fe) and magnesium (Mg) and has a thickness of approximately 2,900 km. The upper mantle’s high temperatures of 2,800-3,200 ⁰C can melt rocks. The mantle is a solid.

The Asthenosphere The semisolid layer in the upper part of the mantle is called the asthenosphere. The upper mantle’s high temperatures of 2,800-3,200⁰C can melt rocks. The asthenosphere is a solid that flows like a liquid. This physical property is called plasticity. Scientists believe that the lithosphere and the crust are able to move slowly over the top of the mantle and asthenosphere. The asthenosphere is about 180 km thick.

The Crust The Crust is the thinnest layer of Earth (8-32 km) and is much cooler in temperature (about ⁰C). The crust is broken into two categories, oceanic crust and continental crust. Continental crust is much thicker than oceanic crust. The crust is broken into many large pieces called tectonic plates. Scientists believe these plate ‘float’ and move around very slowly on the semiliquid asthenosphere. Solid. Oxygen (O 2 ) and Silicon (Si).

The Lithosphere The layer around the asthenosphere is known as the lithosphere. The lithosphere is the solid outer layer of Earth that consists of the crust and the upper mantle. This layer is made up of mostly the elements Oxygen (O 2 ) and silicon (Si). The temperature ranges from ⁰C depending on the depth. The thickness of the lithosphere can be anywhere from km thick.

Oceanic Crust Composition: Mafic Rock- Iron (Fe) and Magnesium (Mg) Thickness: 8-10 km Temperature: ⁰C State of Matter: Solid

Continental Crust Composition: igneous, metamorphic, and sedimentary rocks Thickness: km Temperature: ⁰C State of Matter: Solid