Outer Core
Layers of the Earth
The outer core is about 2,890 and 5,150 km below the Earth's surface. It is a liquid is mainly composed of iron and, nickel. S-waves do not travel through this layer and that is how scientists have inferred that is made of liquid. This layer is approximately 1900 km thick. The temperature of the outer core is 4000-5000 degrees C. The outer core is about 220 km thick. The outer core surrounds the inner core which is the fourth layer of the Earth.