Continental Margin

At the seaward edge of the continental shelf, the ocean floor drops off abruptly along the continental slope. The break point between the shelf and slope is sometimes known as the continental shelf break. The continental slopes are the most dramatic cliffs on the face of the Earth. They may drop from a depth of 656 ft (200 m) to more than 9,840 ft (3,000 m) in a distance of about 62 mi (100 km). In the area of ocean trenches, the drop-off may be even more severe, from 656 ft (200 m) to more than 32,800 ft (10,000 m).

The average slope of sea floor along the continental slope is about 4°, although that value may range from as little as 1° to as much as 25°. In general, the steepest slopes tend to be found in the Pacific Ocean, and the least steep slopes in the Atlantic and Indian Oceans. Sedimentary materials carried to the continental slope from the continental shelf do not remain along the slope (because of its steep sides), but flow downward into the next region, the continental rise.