HYPSOMETRY OF THE CONTINENTAL-SHELF OFF EASTERN NORTH-AMERICA

Areas measured between contours at 20-m intervals on most of the continental shelf off eastern North America were used to construct histograms and cumulative curves of areas of bottom and volumes of overlying water at various depths. The largest and deepest (212-m to 93-m median depths) shelf provinces are those that have undergone glacial erosion; these have most of the overlying water. More typical of continental shelves of the world are those floored by thick sediments; they have median depths between 37 and 40 m and most are broadly convex in profile between the shore and the shelf break. Also convex upward are the belt between the shore and the -100-m contours and the belt between - 20 m and 20 m above sea level. However, the belt between the + 20-m and + 100-m contours and the broader one between the - 100-m and + 100-m contours are concave upward. This geometry is about what would be expected from the known history of marine erosion and deposition on a relatively submergent coast. © 1979.