Archipelagic apron

An archipelagic apron is a fan shaped, gently sloping region of sea floor that surrounds an oceanic island, found particularly in the south Pacific Ocean. The geologist Henry William Menard proposed the name in 1956 because the slope resembles an apron, and while most such surfaces are smooth, some are rough in texture. An apron often occupies a volume many times that of the island rising above it, more than could have come only from material washed off the exposed island, so aprons most likely formed from debris avalanches and pyroclastic flows that were later reworked by turbidity currents; together they make up about eight percent of the area of the Pacific basin.