During the last ice age, a mile - high North American ice sheet, that stretched as far south as Long Island, N.Y., piled so much weight on the Earth that underlying mantle rock flowed slowly outward, away from the ice. (uvm.edu)
Four years before the Russians started punching their way into the Kola crust, the United States had given up on its own deep - drilling program: Project Mohole, an attempt to bore several miles through the Pacific seafloor and retrieve a sample of the underlying mantle. (discovermagazine.com)
«In turn, these reservoirs are fed from deeper layers in the earth's crust and the underlying mantle. (sciencedaily.com)