People live on the outermost layer of Earth called the crust.
There are three main layers of Earth. The three main layers of Earth are the crust, the mantle, and the core. A brief description of each layer is provided below.
Crust: The crust is the rocky outermost layer. The crust is the thinnest layer of Earth. It is about 5 km thick under the ocean and 30 km thick under the continents.
Mantle: The mantle is the middle layer of Earth. It is made of semisolid rock. It is about 2,900 km thick.
Core: The core is subdivided into the inner core and the outer core, which can be distinguished by the following characteristics.
- Outer core: The outer core is the only liquid layer of Earth. It is made of mostly iron and nickel. It is between 2,890 and 5,150 km below the crust and 2,300 km thick.
- Inner core: The inner core is extremely hot and made of mostly solid iron and nickel. It is roughly 5,150 to 6,378 km below Earth’s surface and has a radius of about 1,200 km.