SHOCK DISCOVERY: Huge mountains bigger than Everest found 400 miles BENEATH surface

The mountains push up into layers of rock above, which are much less dense and not as solid than the hilly areas beneath.

Lead author Wenbo Wu, a geoscientist at the California Institute of Technology, said: “We know that almost all objects have surface roughness and therefore scatter light. That’s why we can see these objects – the scattering waves carry the information about the surface’s roughness.

“In this study, we investigated scattered seismic waves travelling inside the Earth to constrain the roughness of the Earth’s 660 kilometre boundary.”

Seismologist Christine Houser, an assistant professor at the Tokyo Institute of Technology who was not involved in this research, added: “They find that Earth’s deep layers are just as complicated as what we observe at the surface.