The outer core
The Outer Core is second from the Inner Core. The Outer Core is the second largest layer next to the Mantle. It is about 1,800 km to about 3,200 km below the crust. The Outer Core is about 2,300 miles thick. The Outer Core is a slow moving sea of mostly iron and nickel liquid-like substance. The temperature is 4,300℃ in the Outer Core.