Continental Shelf

The zone bordering a continent extending from the line of permanent immersion to the depth, usually about 100 m to 200 m, where there is a marked or rather steep descent toward the great depths of the ocean.

The region of the oceanic bottom that extends outward from the shoreline, with an average slope of less than 1:100, to a line where the gradient begins to exceed 1:40 (the continental slope).