Guyot - tablemount - flat top underwater formations - Wikipedia, the free encyclopedia

A guyot /ˈɡiːjoʊ/, also known as a tablemount, is an isolated underwater volcanic mountain (seamount), with a flat top over 200 meters (660 feet) below the surface of the sea. The diameters of these flat summits can exceed 10 km (6 miles).^[1]