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the U.S. Coast Guard Cutter Healy and the Canadian Coast Guard Cutter Louis S Saint Laurent operating in Arctic sea ice, as seen from the ice level

U.S. Extended Continental Shelf Project


  • The mission of the U.S. Extended Continental Shelf (ECS) Project is to establish the full extent of the continental shelf of the United States, consistent with international law.

  • The ECS is that portion of the continental shelf beyond 200 nautical miles. It is an important maritime zone that holds many resources and vital habitats for marine life. Knowledge of the exact extent of the ECS and an improved understanding of its resources is necessary for national security and good management.

  • The process to determine the outer limits of the U.S. ECS requires the collection and analysis of data that describe the depth, shape, and geophysical characteristics of the seabed and sub-sea floor. Since 2003, U.S. agencies have been engaged in gathering and analyzing data to determine the outer limits of the U.S. ECS.

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U.S. Department of State

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