Rugged ‘mountains’ taller than Everest lurk deep inside Earth

Previous work using earthquake waves showed that these seismic signals dance around the boundary 410 miles deep in ways that suggest the rocks below are denser than those above. The picture that has emerged is far different from the standard yellow and red layers seen in most Earth diagrams; much of the upper mantle likely sparkles with vibrant green olivine, while more dark rosy garnets mixed with blue minerals twinkle above the boundary 410 miles down, and earth-toned bridgmanite sits below. To peer into Earth’s innards for this latest work, Wu and his colleagues turned to the reverberations from really big earthquakes.

Source: www.nationalgeographic.com