what is earths core
The outer core of the Earth is a liquid layer about 2,266 kilometers thick. It is made of iron and nickel. This is above the Earth's solid inner core and below the mantle. Its outer boundary is 2,890 km (1,800 mi) beneath the Earth's surface.
Earths Core. The Earths core is difficult to study because it is impossible to drill deeper than a few miles beneath the Earth's surface. The study of earthquake waves moving through the body of the Earth is the major tool used to study the interior of the Earth and its cores.