And that's still over 50 miles (80 km) away from the next layer, the mantle, according to Earth layer data from the USGS. The mantle is a 1,740-mile-thick (2,800 km) layer of dark, dense rock that ...

The beginnings of a strange layer of molten rock deep inside the Earth may have finally been figured out by geoscientists. This layer, known as the D" layer, is about 1,900 miles underneath the ...