The Earth is composed of several distinct layers, which are generally categorized into three main layers, along with sub-layers. Here are the primary layers of the Earth:
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Crust: The outermost layer, which includes the Earth's surface and is relatively thin compared to the other layers. It consists of continental crust (land) and oceanic crust (under the oceans).
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Mantle: Located beneath the crust, the mantle extends to a depth of about 2,900 kilometers (1,800 miles). It is made up of solid but malleable rock and is divided into:
- Upper Mantle: Includes the lithosphere (which includes the crust) and the asthenosphere (a semi-fluid layer).
- Lower Mantle: Extends from about 660 kilometers to the outer core.
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Outer Core: A liquid layer composed mainly of iron and nickel, lying beneath the mantle. It extends from about 2,900 kilometers (1,800 miles) to around 5,150 kilometers (3,200 miles) deep.
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Inner Core: The innermost layer of the Earth, which is solid and primarily composed of iron and nickel. It extends from about 5,150 kilometers (3,200 miles) to the center of the Earth at around 6,371 kilometers (3,959 miles).
These layers vary in composition, temperature, and physical state, contributing to Earth's geological activity, such as tectonic movements and volcanic activity.