A seamount is an underwater mountain that rises at least 1000 meters above the sea floor. Some seamounts rise above the water's surface. Most seamounts are volcanic in orgin; only a few are non-volcanic (caused by uplifting). Seiche (saysh): a series of standing waves (sloshing action) of an enclosed body or partially enclosed body of water caused by earthquake shaking. Seiche action can affect harbors, bays, lakes, rivers, and canals.
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. These are typically formed from extinct volcanos, that rise abruptly and are usually found rising from a seafloor of 1,000 4,000 metres depth. They are defined by oceanographers as independent features that rise to at least 1,000 metres above the seafloor.