Continental Shelf

The continental shelf is the submerged outer edge of a continent. The shelf begins at the shoreline's low tide mark and slants gently beneath the ocean. At the outer edge of the shelf, a continental slope breaks downward to the great ocean depths. The maximum width and the depth of the shelf vary. The depth is generally less than 330 feet (100 meters) to 660 feet (200 meters) deep. The width varies from less than one mile (1.6 kilometers) to several hundred miles.

A continent's position relative to tectonic plate boundaries influences the width and depth of its shelf. A continent has a narrow shelf where it sits on the leading edge of a plate that collides with an oceanic plate. Jolting earthquakes and erupting volcanoes ...