A
seamount is a
mountain rising from the
ocean seafloor that does not reach to the water's surface (
sea level), and thus is not an
island. Seamounts are typically formed from
extinct volcanoes that rise abruptly and are usually found rising from the
seafloor to in height. They are defined by
oceanographers as independent features that rise to at least above the seafloor, characteristically of conical form. The peaks are often found hundreds to thousands of meters below the surface, and are therefore considered to be within the
deep sea. During their evolution over geologic time, the largest seamounts may reach the sea surface where wave action erodes the summit to form a flat surface. After they have subsided and sunk below the sea surface such flat-top seamounts are called "guyots" or "tablemounts"