Continental slope – The slope is “the deepening sea floor out from the shelf edge to the upper limit of the continental rise, or the point where there is a general decrease in steepness” (IHO, 2008). Compared with the relatively flat surface and gentle inclination of the continental shelf, the continental slope dips steeply into the ocean basins at an average angle of around 4° although it may be much steeper locally (35 to 90°). The continental slope (often referred to simply as “the slope”) is commonly dissected by submarine canyons; faulting, rifting and slumping of large blocks of sediment can form steep escarpments, relatively flat terraces and (under certain conditions) basins perched on the slope.
On average, the slope is a narrow band ~41 km wide that encircles all continents and islands. The passive margin slopes of the South Atlantic Ocean are the widest on average (73 km), although the slope attains its greatest width of 368 km in the North Atlantic, where the slope protrudes south of Newfoundland. The most narrow, active margin, slopes are in the Mediterranean and Black Seas (25.8 km). The average width of active slopes (35.6 km) is somewhat less than the average width of passive margin slopes (45.7 km).