Once scientists were able to map the ocean floor, they discovered something surprising. The bottom of the ocean was not a flat, sandy plain stretching between the continents, as many people once thought.

In fact, the ocean floor was rocky and dramatically uneven. Many previously unknown features of the seafloor were discovered.

The Continental Margin The area where the underwater edge of a continent meets the ocean floor.

Extending out from a continent's edge is a gently sloping, shallow area called the continental shelf (F)

This shelf can extend for several hundred yards or several hundred miles.

For every 100 yards you go out into the water, you drop about 3 feet, on average.

Where the water of this shelf meets the land is called, Shoreline.

This is the area anglers refer to as, deep sea fishing. Most of the ocean’s critters live on the shelf.

At the edge of the shelf, the ocean floor drops off in a steep incline called the continental slope (A).

Because of gravity and wave action, all left-over food, garbage and dead plants and critters get swept off the shelf and over this slope.

turbidity current This action is called turbidity current. Turbidity is a fancy word for dirty water.

turbidity current A turbidity current is a flow of water that carries large amounts of sediments.

Just like a stream erodes the banks, turbidity current also creates erosion.

Submarine Canyon The erosion cuts a valley into the continental margin, called a Submarine Canyon.

Submarine canyons Submarine canyons are deep, V- shaped valleys cut into the rock of the continental margin.

Your textbook mentions the Monterey Submarine Canyon off the coast of central California. simon.org/sections/submarineCanyons/map s_graphs.php?sec=schttp:// simon.org/sections/submarineCanyons/map s_graphs.php?sec=sc

The continental slope marks the true edge of the continent, where the rock that makes up the continent stops and the rock of the ocean floor begins.

At the bottom of this 2 to 3 mile drop into the ocean, all that debris from the shelf piles-up.

This pile is referred to as: The Continental Rise.