A Pacific donut hole feeds two nations and ice-age memory
The Bering Sea is a northern Pacific marginal basin of more than two million square kilometres between Alaska and Russia’s Far East, meeting the Arctic at the Bering Strait. Currents, ice, and weather brew a productive ecosystem split among U.S., Russian, and high-seas “Donut Hole” waters.
Together with the strait at its northern end, the Bering Sea marks the boundary between Eurasia and the Americas, the planet's two largest landmasses. It is hemmed in by Alaska to the east and north-east, the Russian Far East and Kamchatka to the west, and the Alaska Peninsula and Aleutian chain to the south, which also cut it off from the Gulf of Alaska. Bristol Bay is the arm between the Alaska Peninsula and Cape Newenham. Islands include the Pribilofs, among them St. Paul, and the Komandorskis, among them Bering Island. It takes its name from Vitus Bering, the Danish-born navigator in Russian service who in 1728 became the first European to explore it systematically, sailing north from the Pacific into the Arctic.
Beneath the surface, a deep basin climbs a narrow slope onto broad continental shelves. The sea holds 16 submarine canyons, including Zhemchug Canyon, the largest anywhere, and a remnant of the ancient Kula plate, which once dived beneath Alaska. On 18 December 2018 a large meteor blew apart 25.6 kilometres above the water, releasing about 49 kilotons of energy.
Its richness comes from two engines. The first is the shelf break, nicknamed the Greenbelt, where cold, nutrient-laden water from the Aleutian basin wells up the slope and mixes with shelf water, sustaining steady phytoplankton growth. The second is seasonal ice: melting ice freshens and layers the water, helping trigger the spring bloom, while the ice itself serves as a surface for algae to grow on and within. Currents, ice and weather together create an exceptionally productive system, divided among American waters, Russian waters and an international pocket in the middle known as the Donut Hole.
During the last glacial period, most scientists believe, sea level fell far enough to expose land where the strait now lies, letting people walk from Asia into North America while mammoths and other big animals crossed in both directions. This Bering land bridge is widely, though not universally, accepted as the first route by which humans reached the Americas.
Source: Bering Sea
