The Sea of ​​Okhotsk is located in the east of the Kamchatka Peninsula, the Kuril Islands to the southeast, the Hokkaido Islands to the south, Siberia to the north, and Sakhalin Island to the southwest. It is connected to the Sea of ​​Japan in the Tatar Strait and the La Peruz Strait (Sogu Strait). The most famous landscape in the area is the floating ice that appears on the sea surface in winter. The sea water is composed of water discharged from the mainland, rainwater, water flowing westward from the Pacific Ocean through the Kuril Islands, and water flowing northward from the Sea of ​​Japan through the La Peruz Strait. Temperate monsoon climate.

Basic introduction

The Sea of ​​Okhotsk (Russian: Лntocфepaoxotckoгo; Romanized writing: okhotskoye; English: color aookhotsk) is a sea in the northwest Pacific Ocean, named after Okhotsk. The Sea of ​​Okhotsk was originally called the Tungus Sea or the Lamut Sea. In the old days, it was called "North Sea" (hokkai), but later it was changed to the North Sea in Europe, so it was now used to use Russian transliteration (ohotsu kai, オホーツク Sea). It was called "Shaohai" and "North Sea" in the Tang Dynasty in China. The Russians entered the Sea of ​​Okhotsk in the 17th century and established the Okhotsk Regional Fleet in 1731, and the base was located in the port of Okhotsk. In 1855, the base of the district fleet was moved to Nikolayevsk (Miaojie).

Geomorphology

The Sea of ​​Okhotsk was formed in the Quaternary period (2.5 million to 10,000 years ago), and experienced many glacier advances and retreats. The seabed slope tilts from north to southwest. According to its geomorphological characteristics, it can be roughly divided into shelf areas, land slope areas and deep water basins. The nearshore shelf areas account for 40% of the total area of ​​the sea area. The central part of the seabed is a land slope area, with some underwater highlands, depressions and troughs scattered. There are two main deep water basins: a wide one on the east side of Sakhalin Island.

The vast Jeliujin Sea Basin has a rugged terrain; on the inside of the Kuril Islands is the Kuril Island Sea Basin, a deep sea plain, and the deepest part of the entire sea area. The seabed sediments are coarse gravel, fine gravel and sand near the coastal zone; the shelf and island shelf areas are mainly sand; the sediments in the deep water sea area are silty mud, silty clay and mud; the bottom of the Kuril Islands generally contains pyroclastic substances, and tuff sediment layers of various particle sizes have been formed in many places.

Earthquakes often occur on the seabed around the Okhotsk Islands, and form huge destructive jinwaves (earthquake and tsunamis). The continental shelf is vast (accounting for more than 42% of the seabed area), about 400 kilometers wide. It is distributed in the north and west; the south of the Kuril Islands is a deep-sea basin (more than 9%); the middle is a strip-shaped continental slope, with alternate seabed depressions and seabed plateaus (more than 48%). The sea current flows from the northeast through the central part of the Kuril Islands to the Pacific Ocean, converges with the currents from the Bering Sea, forming a cold current in the Thousand Islands (common tide); there are warm currents passing through some areas in the south.

Geographical location

The marginal sea in the northwest of the Pacific Ocean is mostly surrounded by different terrain areas of Northeast Asia. The Sea of ​​Okhotsk is bordered by Russia's Siberian coast in the west, from the Heilongjiang River Estuary Bay in the south, and to the Penzhina River Estuary in the north. It is bounded by the Kamchatka Peninsula and the Kuril Islands in the east, from Hokkaido in Japan in the south, and to the Sakhalin Island in the southwest. The Sea of ​​Okhotsk covers an area of ​​1.583 million square kilometers. The average water depth is 777 meters, and the sea water washes the coasts of Japan and Russia.

Most of the continental coasts are high rocky banks, with estuaries of regional rivers that inject into the sea. Such as the Heilongjiang River, the Udi River, the Okhota River, the Jiriga River and the Pinrenna River. The seabed is tilted from north to south and southwest. The north and northwest are continental sheds with a depth of 200 meters, while the rest of the areas (about 70% of the total area) are continental slopes ranging from 200 to 1500 meters deep.

Terrain characteristics

The longest is 2460 kilometers from north to south, the widest is 1480 kilometers from east to west, the area is about 1.528 million square kilometers, and the average water depth is 838 meters. There is a wide continental shelf in the north, and the water depth to the south increases. The water depth in the middle is 1,000-1,600 meters, and the deepest in the east is 3,658 meters. The coastline is relatively straight and the total length is 10,460 kilometers. The larger bays include Sherekhov Bay, Ude Bay, Tai Bay, Akhadmi Bay, etc. The sea water is shallow in the north and south. The average depth is 821 meters, shallow in the north and south, and the deepest in the deepest is 3,521 meters (Qiandao Sea Basin). The water capacity is 1.365 million cubic kilometers. The salinity is 32.8‰-33.8‰.

Sea of ​​Okhotsk under the sunset

The northern sea of ​​Okhotsk is shallow and deep in the south, the northern coast is the continental shelf area, the central continental slope area, and the eastern side of the Sakhalin Island (Sakhalin Island) in the south and the inner side of the Kuril Islands are two deep-water sea basins. The Kuril Islands at the edge of the sea basin are located in the crustal activity zone, with a continental shelf of 200 meters deep in the north and northwest, while the rest of the areas (about 70% of the total area) are continental slopes ranging from 200 to 1500 meters deep. Earthquakes and volcanic activities often occur in the seabed, with 30 active volcanoes and 70 extinct volcanoes. The seabed topography tilts from north to south, and the northern continental shelf is wide. There are famous Kuril Island sea basins in the south, with a deepest reaching 3521 meters. The climate difference between the north and south of the Okhotsk Sea is obvious. The north is at a high latitude and extends into the Asian continent, with a subpolar continental climate. The winter is severely cold and long, and the summer is warm and short

, The annual precipitation is 400-700 mm; the south is temperate marine climate regulated by the ocean, with an annual precipitation of more than 1,000 mm. The average temperature in the north in January is minus 24c and the south is minus 10c; the average temperature in the north in August is 11c and the south is 17c. The dry and cold northwest wind from the mainland in winter can not only stir up large waves on the sea surface, but also cause large-scale cooling, causing most sea areas to freeze. The north generally starts to freeze in November, and the ice age lasts until June next year, and the southern ice age is mostly no more than 3 months. The sea area is frozen or floating ice, which is not conducive to navigation. The sea and sea area is formed due to the intersection of cold currents and warm currents, and thick fog is formed. There are many nutrients in the sea water, which is conducive to the reproduction of marine organisms, and the production of Kamchatka crabs, salmon, herring, cod, plaid, etc. Important ports include Magadan, Okhotsk, etc.

Coast conditionsEdit

Most of the coasts are high and steep; the west bank of Kamchatka Peninsula, the north bank of Sakhalin and Hokkaido Island is low and has many lagoons, and the shoreline is relatively straight. The large bay includes Sherekhov Bay, Sakhalin Bay and Terpenier Bay. There are estuaries of regional rivers that flow into the sea, such as Heilongjiang, Uda River, Okhota River, Gizhiga River and Pinrenna River.

Geological activities edited

The Hong Kong Observatory recorded a violent earthquake at 10:19 am on July 5, 2008. The center of the earthquake was about 380 kilometers westwest of Petropavlovsk, Russia, and the scale of the earthquake was 7.5 magnitude Richter. After preliminary analysis, the epicenter was located in the Sea of ​​Okhotsk (53.9 degrees north latitude and 153.0 degrees east longitude). There are no reports of casualties or damages.

The China Earthquake Network officially determined that at 13:44 on May 24, 2013, the 8.2-magnitude earthquake occurred in the Sea of ​​Okhotsk (54.9 degrees north latitude and 153.3 degrees east longitude), with a depth of 600 kilometers. This earthquake has two significant characteristics: 1. A huge earthquake with a depth of more than 600 kilometers, which is very rare in the history of earthquake observation; 2. Since the focal depth is 600 kilometers (located in the mantle), the seismic wave propagation speed is faster. The energy attenuation slows down, and the huge energy carried by the low-frequency components can spread farther, which makes most parts of my country feel tremor.

Climate characteristicsEdit

Okhotsk Sea Temperature Monsoon Climate. Average temperature: minus 20c in the north and minus 7c in the south in February; 12c in the northeast in August. 18c in the south. Surface water temperature: below 0c in winter, 8-12c in summer. Surface salinity is 25‰-35‰. The sea area freezes from October to June of the following year, with the largest freezing range in March, with 1 meter thick ice. It is foggy from April to August, and there are thick fogs in the north and northwest. There are many blizzards in winter. Irregular sun tides and half-day tides. The maximum tide difference is 12.9 meters (Pinrenna Bay), flow The speed is about 7.5 knots. The current is in a counterclockwise direction, with a flow rate of 0.5-1.5 knots. Annual precipitation: 710 mm in the north and 1040 mm in the south. The annual average temperature varies with latitude, with the north being minus 6c and 5.5c in the south; at the same latitude, the east is 10c higher than the west. The average monthly temperature is the lowest in January, with the northern Serryhof Bay and Uda Bay being minus 24c, while the Kuril Islands and southern Kamchatka being -10c; the highest in August, with the north being 11c and the south being 17c.

Most of the sea surface of the Sea of ​​Okhotsk freezes from October to June of the following year. The northern and western waters are affected by the Asian continent and have a sub-cold continental climate. The average temperature in January and February of winter is minus 20c to minus 24c, and 12-14c from July to August. The annual precipitation is 400-700 mm. The seawater freezing period is as long as 7 months (November to June of the following year), and the ice is 0.8-1m thick. The south and eastern areas are Near the Pacific Ocean, it has a temperate monsoon climate, with an average temperature of minus 5 c to minus 7 c from January to February, and 12-18 c from July to August. The annual water volume is above 1,000 mm. Due to the intersection of cold currents and warm currents, there is thick fog during the melting period, and there is flowing ice activity, which is unfavorable to navigation. The surface salinity of the seawater is 25‰-27‰ near Sakhalin Island. 32-‰33‰ near Kamchatka and 33‰ in the central part.

At the same time, the monsoon climate is very significant. The winter monsoon blows from land to the ocean, with strong winds and long duration; in summer, there are more sea breezes and strong storms in autumn. The wind speed reaches 20-30 meters/sec and the waves are as high as 8-12 meters. In addition, the sea area is susceptible to the attack of Jinwaves (earthquakes and tsunamis), and the waves are as high as 20 meters in an instant. The wavelength is several kilometers and the propagation speed is 400-800 kilometers/h, causing huge damage to coastal areas, especially the Kuril Islands.

There is severe ice, and almost all sea ice is present in the entire sea area. In the north, it starts to freeze in November, with an ice-making period of 280 days, with an ice thickness of 0.8-1 meter; Kamchatka and the Kuril Islands are ice-free areas, and the annual ice-making period does not exceed 3 months on average. In severe winter, sometimes northwest wind blows the ice-floating to the Kuril Islands, blocking some straits. In summer, sea ice remains only near the Shantal Islands, and there is no ice in other sea areas...

Affected by the extreme climate of the Asian continent, the northeast, northern and western waters of Okhotsk are severely cold in winter. From October to April of the following year, the temperature in these waters was very low and the sea water was frozen. The southern and southeastern waters were close to the Pacific Ocean and had a relatively mild marine climate. The average temperature in the northern waters in February was minus 20c and 12c in August. The average temperature in the southern waters in February was minus 7c and 18c in August. The sea water began to freeze at the end of October, and the freezing was the worst in March.

The average water depth of the Sea of ​​Okhotsk is 821 meters, with a maximum water depth of 3916 meters. The surface currents in the sea area generally flow from the northeast through the central part of the Kuril Islands to the Pacific Ocean, converging with the currents from the Bering Sea to form a cyclonic circulation. The sea water in the Sea of ​​Okhotsk is composed of water discharged from the mainland, rainwater, water flowing westward from the Pacific Ocean through the countless straits of the Kuril Islands, and water flowing northward from the Sea of ​​Japan through the La Peruz (also known as the Sogo Valley) strait. Affected by these currents, the water temperature in the eastern half of the sea is higher than that in the western half, and the sea water generally flows counterclockwise. The sea water converges from the Pacific Ocean, especially the sea water converges between the eastern and central part of the Kuril Islands, forms a turbulent rapid flow on several tributaries in the eastern part and flows northward, while in the west, the river water injected from the Siberian continent merges into similar rapids and flows southward.

The sea current is roughly a cyclonic circulation. After the warm water of the Pacific Ocean flows into the sea through the northern Strait of the Kuril Islands, it is divided into two branches:

One branch pointed directly to John Island northwest. The strength continued to weaken. The other branch went north and turned west and southwest along the northern coast. On the way to the south of the coast, it continuously included the freshwater of various rivers (especially the runoff of Heilongjiang), and then went south along Sakhalin Island. This was a cold coastal current; and a small part flowed from the north side of the La Peruz Strait (Songgu Strait) to the Sea of ​​Japan.

The warm water of the Sea of ​​Japan flows into the sea area from the south side of the La Peruz Strait (Soya Strait), and flows eastward along the northern shore of Hokkaido, which is the Soya Sea current. The flow rate can reach 50-90 cm/sec. Therefore, it forms a cyclonic total circulation. The near-shore is greater than the far-sea. The far-sea current is generally 5-10 cm/sec. The flow direction is relatively stable. The water exchange between this sea area and the Pacific Ocean mainly passes through the Kuril Islands Strait. As for the entire archipelago, the upper layer enters north and exits south; the deep layer mainly flows in from the Pacific Ocean, which is different from the way La Peruz Strait (Soya Strait) enters south and exits north and exits from the Sea of ​​Japan.

The water mass mainly includes surface water, middle water and deep Pacific water. The surface water (0-150 or 200 meters layer) is formed by vertical convection of sea water in winter. The temperature and salt characteristic values ​​are -1.7-0.6c and 32 respectively. The middle water (200-800 meters layer) is formed by mixed denaturation of the upper water inflowing in the Pacific. The temperature and salt characteristic values ​​are 0.1-2c and 33.3-33.8 respectively. The Pacific deep water (800 meters deep) is formed by denaturation of the deep Pacific water inflowing in the Pacific. It is characterized by high temperature (about 2.4c), low oxygen (amp;lt;1 ml/liter), and salinity is 34.3‰-34.4‰…

Tide waves are transmitted from the Pacific Ocean, and the tides are mainly irregular full-day tides. Only in the north, the northwest coast and near the Shantal Islands are irregular half-day tides. The tide difference is large in the north and small in the south. Near the astronomical corner of Pinren Bay, the tide difference can reach 13 meters. The Shantal Islands can also reach 7 meters, while the southern sea area is only 0.8-2.5 meters. The tide is divided into half-day tide and full-day tide. The flow rate varies from place to place, the outer sea is only 5-10 cm/sec, and the tide currents of the Straits and Bay mouths can reach 2-4 meters/sec.

There are many nutrients in the seawater in this sea area, which is conducive to the reproduction of marine organisms. The phytoplankton reaches 20 grams/meter, mainly belonging to the diatomaceae, followed by dinoflagellates. The biomass of phytoplankton can reach 1-3 grams/meter in some areas. The total biomass of benthic organisms in the sea area reaches 200 million tons. Among various animals, molluscs are the most, followed by echinoderms and polyhedral anterior animals. The more economical value are Kamchatka crabs, blue crabs and certain molluscs. There are about 300 fish species, including salmon, herring, voles, and plaids, all of which have important economic value. In addition, there are mammals such as sperm whales, sea lions and seals.

The continental shelf has abundant fishery resources. There are many cold fish, mainly herring, salmon, trout and other fish. There is the world's largest crabbing farm near Kamchatka in the east. It is rich in salmon, trout, herring, cod and capelin. The coastal ports include Russia's Magadan, Okhotsk, Korsakov and Japan's net walks. There are many sea dogs, beluga whales, sea donkeys, seals and other animals. It was developed late and only sailed from Okhotsk to Kamchatka in 1713. Important ports include the Soviet Union's Magadan, Okhotsk, and Nikolayevsk (Miaojie).

Most of the fishing ports in Korsakov and Japanese net walks and vermicelli are fishing ports. The waters near the Kamchatka Peninsula are rich in fish and crabs. The Okhotsk sea water in the warm season is quite suitable for marine life growth. The marine plants here include seaweed and seaweed, and sea animals include crayfish, mussels, crabs, sea urchins, coral polyps and a variety of fish, including salmon, herring, green cod, halibut, cod, capelin and cow, as well as crabs and brown shrimps, all of which are of high economic value. The Okhotsk Sea also has whales, seals, sea lions and sea dogs.

The Sea of ​​Okhotsk is the edge sea in the northwest of the Pacific Ocean. It is located between the Kuril Islands and the Asian continent. It connects to the Sea of ​​Japan through the Sogoku Strait (La Peruz Strait) and connects to the Pacific Ocean through the various straits of the Kuril Islands. There are regular shipping on the Okhotsk Sea to communicate with ports in the Far East. The main ports along the coast are Magadan and Okhotsk in the Bay of Nagayevo. Korkov in Sakhalin Island and North Kurilsk in the Kuril Islands.

-Kojilsk and South Kurilsk (yuzhno-Kojilsk) are also very important. Large chunks of ice floes hinder shipping in winter, and thick fog in summer hinders traffic. The Okhotsk Sea is located in the east of the Kamchatka Peninsula, the Kuril Islands in the southeast, the Hokkaido Island in the south, the Siberia in the north, and the Sakhalin Island in the southwest. The Okhotsk Sea is connected to the Pacific Ocean through the Kuril Islands Straits, and is connected to the Sea of ​​Japan in the Tatar Strait and the La Peruz Strait (Sogu Strait). The most famous landscape in the area is the floating ice floes appearing on the sea in winter.
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