Oyashio Current
Encyclopedia
Kuril Islands
The Kuril Islands , in Russia's Sakhalin Oblast region, form a volcanic archipelago that stretches approximately northeast from Hokkaidō, Japan, to Kamchatka, Russia, separating the Sea of Okhotsk from the North Pacific Ocean. There are 56 islands and many more minor rocks. It consists of Greater...
current, is a cold subarctic ocean current
Ocean current
An ocean current is a continuous, directed movement of ocean water generated by the forces acting upon this mean flow, such as breaking waves, wind, Coriolis effect, cabbeling, temperature and salinity differences and tides caused by the gravitational pull of the Moon and the Sun...
that flows south and circulates counterclockwise in the western North Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
. It collides with the Kuroshio Current
Kuroshio Current
The Kuroshio is a north-flowing ocean current on the west side of the North Pacific Ocean. It is similar to the Gulf Stream in the North Atlantic and is part of the North Pacific ocean gyre...
off the eastern shore of Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
to form the North Pacific Current
North Pacific Current
The North Pacific Current is a slow warm water current that flows west-to-east between 40 and 50 degrees north in the Pacific Ocean. The current forms the southern part of the North Pacific Subpolar Gyre...
(or Drift). This cold current flows through Bering Strait in the southern direction and transports cold water of the Arctic Sea into the Pacific ocean. The waters of the Oyashio Current originate in the Arctic Ocean
Arctic Ocean
The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...
and flow southward via the Bering Sea
Bering Sea
The Bering Sea is a marginal sea of the Pacific Ocean. It comprises a deep water basin, which then rises through a narrow slope into the shallower water above the continental shelves....
. The current has an important impact on the climate of the Russian Far East
Russian Far East
Russian Far East is a term that refers to the Russian part of the Far East, i.e., extreme east parts of Russia, between Lake Baikal in Eastern Siberia and the Pacific Ocean...
, mainly in Kamchatka
Kamchatka Peninsula
The Kamchatka Peninsula is a peninsula in the Russian Far East, with an area of . It lies between the Pacific Ocean to the east and the Sea of Okhotsk to the west...
and Chukotka
Chukchi Peninsula
The Chukchi Peninsula, Chukotka Peninsula or Chukotski Peninsula , at about 66° N 172° W, is the northeastern extremity of Asia. Its eastern end is at Cape Dezhnev near the village of Uelen. It is bordered by the Chukchi Sea to the north, the Bering Sea to the south, and the Bering Strait to the...
, where the northern limit of tree growth is moved up to ten degrees south of the latitude it can reach in inland Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...
. The waters of the Oyashio Current form probably the richest fishery
Fishery
Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...
in the world owing to the extremely high nutrient content of the cold water and the very high tides (up to ten metres) in some areas - which further enhances the availability of nutrients. However, the Oyashio Current also causes Vladivostok
Vladivostok
The city is located in the southern extremity of Muravyov-Amursky Peninsula, which is about 30 km long and approximately 12 km wide.The highest point is Mount Kholodilnik, the height of which is 257 m...
to be the most equatorward port
Port
A port is a location on a coast or shore containing one or more harbors where ships can dock and transfer people or cargo to or from land....
to seasonally freeze and require icebreaking ships
Icebreaker
An icebreaker is a special-purpose ship or boat designed to move and navigate through ice-covered waters. Although the term usually refers to ice-breaking ships, it may also refer to smaller vessels .For a ship to be considered an icebreaker, it requires three traits most...
to remain open in winter. Nonetheless, this has relatively little effect on the fish yield through the Sea of Okhotsk because the large tides mean freezing does not occur so easily.
Another important feature of the Oyashio Current is that during glacial periods, when lower sea level
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...
causes the formation of the Bering land bridge
Bering land bridge
The Bering land bridge was a land bridge roughly 1,000 miles wide at its greatest extent, which joined present-day Alaska and eastern Siberia at various times during the Pleistocene ice ages. Like most of Siberia and all of Manchuria, Beringia was not glaciated because snowfall was extremely light...
, the current cannot flow and in the regions the Oyashio affects today, the level of cooling with the onset of glacial conditions (after an interglacial) is much less than in other areas of the Earth at similar latitudes. This allowed Tōhoku
Tohoku region
The is a geographical area of Japan. The region occupies the northeastern portion of Honshu, the largest island of Japan. The region consists of six prefectures : Akita, Aomori, Fukushima, Iwate, Miyagi and Yamagata....
and Hokkaidō
Hokkaido
, formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan's second largest island; it is also the largest and northernmost of Japan's 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaido from Honshu, although the two islands are connected by the underwater railway Seikan Tunnel...
, which were the only areas of East Asia
East Asia
East Asia or Eastern Asia is a subregion of Asia that can be defined in either geographical or cultural terms...
that receive enough snowfall to potentially form glaciers, to remain unglaciated except at high elevations during periods when Europe and North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
were largely glaciated. This lack of glaciation explains why, despite its present climate being much colder than most of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, East Asia has retained 96 percent of Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
tree genera, whereas Europe has retained only 27%.
See also
- Ocean currentOcean currentAn ocean current is a continuous, directed movement of ocean water generated by the forces acting upon this mean flow, such as breaking waves, wind, Coriolis effect, cabbeling, temperature and salinity differences and tides caused by the gravitational pull of the Moon and the Sun...
- Oceanic gyres
- Physical oceanographyPhysical oceanographyPhysical oceanography is the study of physical conditions and physical processes within the ocean, especially the motions and physical properties of ocean waters.Physical oceanography is one of several sub-domains into which oceanography is divided...
, the Imperial Japanese NavyImperial Japanese NavyThe Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...
destroyer named after the Current.