The Arctic Ocean is bordered by several significant marginal seas. Four prominent ones lie entirely or partly within the Arctic Circle:
Located between Canada’s Baffin Island and Greenland, Baffin Bay is the world’s largest bay, covering over 1.2 million km² (470,000 sq mi). It connects the Arctic Ocean to the Atlantic via Davis Strait.
Situated between Greenland, Jan Mayen, Svalbard, and Iceland, the Greenland Sea spans about 1.2 million km² (460,000 sq mi). It contains the Fram Strait, the deepest point in the Arctic Ocean at over 5,500 meters (18,000 ft).
North of Norway and Russia, the Barents Sea covers roughly 1.4 million km² (540,000 sq mi). It is renowned for rich fisheries and substantial oil and gas reserves.
Between Novaya Zemlya and Severnaya Zemlya, the Kara Sea extends over 880,000 km² (340,000 sq mi). It is relatively shallow (average depth <100 m) and serves as an important Arctic shipping route.
These seas play critical roles in Arctic climate, ecology, and geopolitics.