Undersea mountain range

Undersea mountain ranges are mountain ranges that are mostly or entirely underwater, specifically under the surface of an ocean. Ranges that originate from current tectonic forces are often called mid ocean ridges, while those formed by past, now submerged volcanism are known as seamount chains; the largest and best known undersea mountain range is the Mid-Atlantic Ridge, a mid ocean ridge. Undersea mountain ranges, like their counterparts on land, are sites of frequent volcanic and earthquake activity.