The Arctic Ocean is ringed by broad shelf seas that open toward its deep central basin. Moving clockwise from the Atlantic side, a map commonly shows the Barents, Kara, Laptev, East Siberian, Chukchi and Beaufort seas, followed by waters around the Canadian Arctic Archipelago and Greenland. The Greenland Sea is often included in Arctic geography even though it also provides a direct connection to the North Atlantic.
No single boundary scheme settles every edge. Hydrographic charts, sea-ice products and ecosystem assessments divide the region for different purposes. The NOAA Arctic Report Card, for example, groups marginal seas into Atlantic and Pacific sectors when comparing summer surface temperatures. Other maps treat Baffin Bay, Hudson Bay or the Bering Sea as adjoining Arctic regions rather than arms of the Arctic Ocean itself.
What a marginal sea is
A marginal sea occupies an ocean’s edge and is partly bounded by land, islands, underwater ridges or changes in seafloor form. Most Arctic marginal seas lie across continental shelves, where water is much shallower than in the central Canada and Eurasian basins. Their open northern sides exchange water and sea ice with the ocean interior.
The names provide manageable geographic units rather than sealed containers. Currents cross their mapped limits and drifting ice can move from one sea to another. Argo’s guide to ocean-floor topography explains why shelf breaks and submarine ridges often offer more physical context than a boundary drawn across open water.
Most of the named seas are shallower than the central Arctic basins because they cover flooded edges of the continents. A shelf sea can still contain deep troughs, islands and steep breaks. The label describes regional position, not one uniform depth or ice condition.
The Barents and Greenland seas face the Atlantic
The Barents Sea lies north of Norway and northwestern Russia, between the Norwegian Sea and the Kara Sea. Warm Atlantic water enters from the southwest, making the western Barents notably different from shelf seas farther east. The Svalbard and Franz Josef Land archipelagos frame much of its northern side, while Novaya Zemlya separates it from the Kara Sea.
The Greenland Sea occupies the deep passage east of Greenland and west of Svalbard. It connects the Arctic and North Atlantic through a region of strong water exchange. Some references describe it as an Arctic marginal sea; others place it within the North Atlantic. An Arctic Council marine geography report lists Greenland Sea among the waters adjacent to the Arctic basin while also distinguishing neighboring Norwegian and Iceland seas.
That report’s circumpolar sea sequence is useful for orientation, but it is not the only valid regionalization. Ecological maps may split the East Greenland shelf from the deep Greenland Sea because species distributions and currents do not follow one simple hydrographic label.
The Kara Sea begins the Russian shelf sequence
The Kara Sea lies east of Novaya Zemlya and north of western Siberia. The Severnaya Zemlya archipelago separates its eastern edge from the Laptev Sea. Large Russian rivers, especially the Ob and Yenisey, deliver freshwater and sediment to this shallow shelf, producing strong coastal gradients during the ice-free season.
On a bathymetric map, the Kara Sea appears as part of the broad Eurasian continental margin rather than the deep central ocean. Sea-ice maps often combine it with the Barents or Laptev in operational regions. The U.S. National Ice Center’s Arctic ice products divide the region for operational analysis, illustrating how boundaries can differ by purpose.
The Laptev Sea borders central Siberia
The Laptev Sea extends from Severnaya Zemlya eastward toward the New Siberian Islands. The Lena River enters through a large delta on its southern coast. Freshwater from the river affects nearshore salinity, while winds and ice movement connect the shelf to the deeper Arctic beyond its northern margin.
Its coastline sits along a broad, shallow shelf that freezes extensively in winter. Summer does not produce the same open-water pattern every year. Argo’s account of ocean zones helps distinguish these horizontal named regions from depth-based zones in the water column.
The East Siberian Sea spans a wide shallow shelf
The East Siberian Sea lies between the New Siberian Islands and Wrangel Island. It fronts a long stretch of northeastern Siberia and covers one of the broadest shelf areas in the Arctic. Rivers are smaller than the Lena or Ob, yet they still influence coastal water and sediment.
The line between the Laptev and East Siberian seas follows island geography more clearly than their open northern limits. Those northern boundaries are hydrographic conventions. The International Hydrographic Organization’s approved Limits of Oceans and Seas gives standardized lines for both seas, while maps made for other purposes can use different regions. A single map line should not be treated as universal.
The Chukchi Sea connects through Bering Strait
The Chukchi Sea lies between northeastern Russia and northwestern Alaska. Bering Strait forms its narrow southern gateway to the Pacific. Water moving north through the strait carries heat, nutrients and organisms from the Bering Sea into the Arctic system.
Wrangel Island helps mark its western side, while Alaska’s Point Barrow area separates it from the Beaufort Sea to the east. The Chukchi is shallow over most of its area. Its biological productivity and seasonal ice reflect the combined influence of Pacific inflow, sunlight and nutrient availability.
The Beaufort Sea follows Alaska and Canada
The Beaufort Sea extends along northern Alaska and northwestern Canada. The Mackenzie River enters through its delta in Canada, adding a major freshwater plume to the shelf. Offshore, the seafloor descends toward the Canada Basin.
Maps differ on the Beaufort’s eastern transition into waters of the Canadian Arctic Archipelago. Sea-ice services may draw operational boundaries that are convenient for forecasting, while ecosystem assessments follow habitat or species distributions. Those approaches can both be useful without placing the boundary in exactly the same position.
Baffin Bay, Hudson Bay and the Bering Sea sit at disputed edges
Baffin Bay lies between Greenland and Baffin Island, linked southward to the Labrador Sea by Davis Strait. It is central to Arctic navigation and ecology, but many ocean maps associate it with the North Atlantic. Arctic marine assessments commonly include it because of sea ice and Arctic species.
Hudson Bay is a large inland sea connected to the Atlantic through Hudson Strait. Its climate and seasonal ice make it part of many definitions of the Arctic region. Hydrographically, however, it is not usually presented as one of the seven principal marginal seas directly surrounding the central Arctic Ocean.
The Bering Sea lies south of Bering Strait in the North Pacific. NOAA’s 2025 Arctic strategy explicitly includes it within the broader Arctic Region used by that agency. A map of Arctic Ocean arms may leave it outside because the strait marks the ocean-basin connection. Both treatments are defensible once the map’s purpose is stated.
How to compare Arctic sea maps
Start with the legend and publication. A navigation chart aims to define named waters, while a sea-ice chart divides the area for monitoring. An ecosystem map may use large marine ecosystems whose borders follow biological or management needs. The Arctic Council ecosystem map includes the central ocean beside regional units such as the Chukchi, Beaufort and Baffin Bay-Davis Strait.
Each named sea contains living communities as well as water and ice. Argo’s planned guide to ocean biotic factors follows the organisms and interactions across such boundaries. For geography, the seven-sea sequence remains the clearest core orientation, provided outer regions are labeled according to the scheme actually used.
Readers comparing two maps should expect small disagreements near open-water borders and larger differences at the region’s southern edge. A clear title, legend and source date make those choices visible. Apparent conflict often reflects a different classification purpose rather than a newly discovered coastline.
