Guyot

A guyot is a flat-topped seamount, a former volcanic island whose summit was planed flat by wave erosion at sea level before the seafloor subsided and carried it into deep water. Harry Hess named the feature in the 1940s after geographer Arnold Guyot. The flat top, now hundreds to over a thousand meters below the surface, dates the island’s drowning and records the subsidence of cooling, aging oceanic lithosphere as it moves off a hot spot. Guyots cluster along hot-spot tracks and in the western Pacific, and their capping carbonate platforms have been sampled by ocean drilling to date the subsidence.