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How wide is the average continental shelf?
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continental shelf
The broad, gentle pitch of the continental shelf gives way to the relatively steep continental slope. The more gradual transition to the abyssal plain is a sediment-filled region called the continental rise. The continental shelf, slope, and rise are collectively called the continental margin.
The average width of a continental shelf is approximately 65 to 75 km (about 40 to 45 miles).12
Because continental shelves are essentially extensions of the continental landmass beneath the ocean, their width varies significantly depending on the adjacent coastal geography. They tend to be narrow and steep off mountainous coasts, such as the western coast of the United States, where they may measure only about 32 km (20 miles) wide. Conversely, they are typically broader and more level offshore from plains, with some regions extending more than 120 km (75 miles). The world's largest continental shelf is found off the coast of Siberia, extending up to 1,500 km (about 930 miles) into the Arctic Ocean.12