Mount Siple is a potentially active Antarctic shield volcano, rising to 3,110 metres (10,203 ft) and dominating the northwest part of Siple Island, which is separated from the Bakutis Coast, Marie Byrd Land, by the Getz Ice Shelf. Its youthful appearance strongly suggests that it last erupted in the Holocene. It is capped by a 4-by-5-kilometre (2.5 mi × 3.1 mi) summit caldera, and tuff cones lie on the lower flanks.[2] Its massive volume of 1,800 cubic kilometres (430 cu mi) is comparable to that of Mount Erebus.