Guyot

In marine geology, a guyot (/ˈɡiː.oʊ, ɡiːˈoʊ/),[1][2] also called a tablemount, is an isolated underwater volcanic mountain (seamount) with a flat top more than 200 m (660 ft) below the surface of the sea.

Guyots were first recognized in 1945 by Harry Hammond Hess, who collected data using echo-sounding equipment on a ship he commanded during World War II.

[3] Seamounts are made by extrusion of lavas piped upward in stages from sources within the Earth's mantle, usually hotspots, to vents on the seafloor.

When an undersea volcano grows high enough to be near or breach the ocean surface, wave action or coral reef growth tend to create a flat-topped edifice.

In addition, the erosive effects of waves and currents are found mostly near the surface: the tops of guyots generally lie below this higher-erosion zone.

[9] One guyot in particular, the Great Meteor Tablemount in the Northeast Atlantic Ocean, stands at more than 4,000 m (13,000 ft) high, with a diameter of 110 km (68 mi).