Quiz: Remember the definition of mal de mer?
"flat-topped submarine mountain," 1946, named for Swiss geographer/geologist Arnold Guyot (1807-1884).
A flat-topped, extinct submarine volcano having an elevation of over 1,000 m (3,280 ft) above the ocean floor. Guyots are thought to form as volcanos in sea-floor spreading zones and to become extinct as they move away from the spreading zones through plate tectonic forces. Their flat tops are believed to form by the erosional action of waves when they initially project above sea level.
isolated submarine volcanic mountain with a flat summit more than 200 m (660 feet) below sea level. Such flat tops may have diameters greater than 10 km (6 miles). (The term derives from the Swiss-American geologist Arnold Henry Guyot.)