The Chukchi Sea Shelf or Chukchi Shelf is the westernmost part of the

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

of the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

and the easternmost part of the continental shelf of

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

. Within this shelf, the 50-mile Chukchi Corridor acts as a passageway for one of the largest marine mammal migrations in the world. The main geological features of the Chukchi Shelf are the

Hope Basin The Hope Basin is a geological feature of the Chukchi Sea Shelf. It lies off the Chukchi Sea coast of Alaska. Its area extends from the outer continental shelf of the Seward Peninsula for about westwards off the coast of Chukotka towards Wrangel ...

and the Herald Thrust, a basement uplift cored by

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

thrust fault A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Thrust geometry and nomenclature Reverse faults A thrust fault is a type of reverse fault that has a dip of 45 degrees or less. If ...

s. The latter is named after Herald Island. Off the northwestern

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

n coast there is a

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

rift basin In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben wi ...

, the Hannah Trough. To the north of Alaska the Chukchi Shelf extends to form the

Chukchi Plateau The Chukchi Plateau or Chukchi Cap is a large subsea formation extending north from the Alaskan margin into the Arctic Ocean. The ridge is normally covered by ice year-round, and reaches an approximate bathymetric prominence of 3,400 m with i ...

which protrudes into the

Arctic Ocean The Arctic Ocean is the smallest and shallowest of the world's five major oceans. It spans an area of approximately and is known as the coldest of all the oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, a ...

geological zone. The Chukchi Shelf is shared between

and the

according to the 1990

USSR–USA Maritime Boundary Agreement The Russia–United States maritime boundary was established by the June 1, 1990 USA/USSR Maritime Boundary Agreement (since Russia declared itself to be the successor of the Soviet Union). The United States Senate gave its advice and consent to ...

50-Mile Chukchi Corridor

The Chukchi Corridor is a 50-mile wide strip of ocean offshore of Northwest Alaska that acts as a passageway for one of the largest marine mammal migrations in the world.

Geography

Following the Chukchi Sea coast, the Chukchi Corridor stretches from Point Hope, Alaska to Utqiagvik, Alaska. From winter through early summer, the area is covered in sea ice with recurring openings in the ice that allow wildlife to migrate north from the Bering Sea to areas of the Chukchi or Beaufort seas during spring and early summer

Fauna

The Chukchi Sea coastline serves as an essential corridor for marine mammals like

bowhead whale The bowhead whale (''Balaena mysticetus'') is a species of baleen whale belonging to the family Balaenidae and the only living representative of the genus ''Balaena''. They are the only baleen whale endemic to the Arctic and subarctic waters, ...

beluga whale The beluga whale () (''Delphinapterus leucas'') is an Arctic and sub-Arctic cetacean. It is one of two members of the family Monodontidae, along with the narwhal, and the only member of the genus ''Delphinapterus''. It is also known as the whi ...

Pacific walrus The walrus (''Odobenus rosmarus'') is a large flippered marine mammal with a discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. The walrus is the only living species in the fa ...

, and

bearded seal The bearded seal (''Erignathus barbatus''), also called the square flipper seal, is a medium-sized pinniped that is found in and near to the Arctic Ocean. It gets its generic name from two Greek words (''eri'' and ''gnathos'') that refer to its h ...

s. It is also an important hunting area for indigenous subsistence hunters. This region includes biologically important gray whale feeding and reproduction habitats Many bird species navigate the Chukchi Corridor to migrate to the North Slope for summer breeding As a region with substantial seafloor productivity, the Chukchi Corridor is an important nursery habitat for

forage fish Forage fish, also called prey fish or bait fish, are small pelagic fish which are preyed on by larger predators for food. Predators include other larger fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the food ...

species,

Arctic cod ''Arctogadus glacialis'', known also with ambiguous common names Arctic cod and polar cod, is an Arctic species of fish in the cod family Gadidae, related to the true cod (genus ''Gadus''). ''Arctogadus glacialis'' is found in icy water. They gr ...

, and

Saffron cod The saffron cod ''(Eleginus gracilis)'' is a commercially harvested fish closely related to true cods (genus ''Gadus''). It is dark grey-green to brown, with spots on its sides and pale towards the belly. It may grow to 55 cm and weigh up to ...

. Saffron and Arctic cod are critical to the Arctic marine food web.North Pacific Fishery Management Council
"Fishery Management Plan for Fish Resources of the Arctic Management Area"
North Pacific Fishery Management Council, 2009. Retrieved 16-09-2016.

Importance

The Chukchi Corridor is an extremely important region for subsistence hunting for the communities of

Point Hope Point Hope ( ik, Tikiġaq, ) is a city in North Slope Borough, Alaska, United States. At the 2010 census the population was 674, down from 757 in 2000. In the 2020 Census, population rose to 830. Like many isolated communities in Alaska, the c ...

Point Lay Point Lay (''Kali ''in Inupiaq- "Mound") is a census-designated place (CDP) in North Slope Borough, Alaska, United States. At the 2010 census the population was 189, down from 247 in 2000. Geography and climate Point Lay is located at (69.7410 ...

, Wainright, and Utqiagvik, Alaska. Studies show that Inupiaq rely extensively on areas in the Chukchi Corridor for hunting throughout the year. The

National Marine Fisheries Service The National Marine Fisheries Service (NMFS), informally known as NOAA Fisheries, is a United States federal agency within the U.S. Department of Commerce's National Oceanic and Atmospheric Administration (NOAA) that is responsible for the stew ...

designated areas along the entire Chukchi coast out to 15–30 miles offshore as

Essential Fish Habitat Essential Fish Habitat (EFH) was defined by the U.S. Congress in the 1996 amendments to the Magnuson-Stevens Fishery Conservation and Management Act, or Magnuson-Stevens Act, as "those waters and substrate necessary to fish for spawning, breeding, ...

(EFH) for saffron cod. In 2001, the

U.S. Fish and Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with oth ...

designated Ledyard Bay as critical habitat for

spectacled eider The spectacled eider (pronounced ) (''Somateria fischeri'') is a large sea duck that breeds on the coasts of Alaska and northeastern Siberia. The spectacled eider is slightly smaller than the common eider at 52–57 cm (20–22 inches) in l ...

s. Currently, part of the corridor is protected from oil and gas activities. On January 27, 2015, President Obama, using his authorities under the

Outer Continental Shelf Lands Act {{Short pages monitor