Arctic Ocean
The Arctic Glacial Ocean, or simply Arctic Ocean, is the northernmost and smallest part of the world ocean on the planet. It is found mainly north of the Arctic Circle, occupying the area between Europe, Asia and North America. It covers some 14,056,000 km² in area and its depths range between 2,000 m and 4,000 m in the central region, and 100 m on the continental shelf. Its average depth is 1,205 m below sea level.
This ocean borders the northern part of the Atlantic, receiving large bodies of water through the Fram Strait and the Barents Sea. It is limited by the Bering Strait, between Chukotka (Russia) and Alaska (USA), which separates it from the Pacific; along the north coast of Alaska and Canada. It also borders the northern coastline of Europe and Asia.
Large masses of ice protect this ocean from atmospheric influences throughout the year. In its central part, ice caps up to four meters thick can be found. Large ice sheets are usually formed by large ice packs sliding over each other.
Winter temperatures are usually around −50 °C due to strong winds from Siberia (Russia); while in the summer they can barely exceed 0 °C; while on the continental shelf temperatures of up to 30 °C can occur.
Geography
The Arctic Ocean occupies a roughly circular basin and extends over an area of about 14,056,000 square kilometers, nearly the size of Russia. The coastline is 45,389 kilometers long. It is surrounded by the masses terrestrial of Eurasia, North America, Greenland and by several islands. Generally considered to include Baffin Bay, Barents Sea, Beaufort Sea, Chukotka Sea, East Siberian Sea, Greenland Sea, Hudson Bay, Hudson Strait, Kara Sea, the Laptev Sea, the White Sea and other water complexes. It is connected to the Pacific Ocean through the Bering Strait and to the Atlantic Ocean through the Greenland Sea and the Labrador Sea.
Underwater Traits
A mid-ocean ridge, the Lomonosov Ridge, separates the deep marine North Polar Basin into two ocean basins: the Eurasian Ocean Basin, which is between 4,000 and 4,500 meters deep, and the Asiatic-American (sometimes called the North American or Hyperborean Basin), about 4000 meters deep. The bathymetry of the ocean floor is marked by fault ridges, abyssal zone plains, ocean depths, and basins. The average depth of the Arctic Ocean is 1038 meters. The deepest point is in the Eurasian Basin, with 5450 meters.
The two major basins are further subdivided by ridges into the Canadian Basin (between Alaska/Canada and the Alpha Ridge), the Makarov Basin (between the Alpha and Lomonosov Ridges), the Fram Basin (between the Lomonosov Ridge and Gakkel Ridge) and the Nansen Basin (Amundsen Basin) (between the Gakkel Ridge and the continental shelf including Franz Joseph Land).
History
According to studies carried out by specialists from the University of Oxford (United Kingdom) and the Royal Netherlands Institute for Marine Research, the Arctic Ocean enjoyed, some seventy million years ago, temperatures similar to those it is today in day they are in the Mediterranean Sea, with measurements of about 15 °C; and temperatures of about 20 °C about twenty million years ago.
The researchers came to this conclusion after studying organic materials found in the mud of islet ice in the Arctic Ocean. It is not yet known why these temperatures occurred at that time, but it is believed that the culprit may have been the greenhouse effect derived from a high concentration of carbon dioxide in the atmosphere (the problem with this hypothesis is the extraordinarily minimal effect carbon dioxide greenhouse).
North America
Human occupation in the polar region of North America dates back to at least between 17,000 and 50,000 years ago, during the Wisconsin Ice Age. At this time, falling sea levels allowed people to cross the Bering Land Bridge linking Siberia to Alaska, leading to the peopling of the Americas.
Early Paleo-Eskimo groups included the Pre-Dorset (c. 3200-850 BCE), the Saqqaq culture of Greenland (2500-800 BCE), the Independence I and Independence II cultures of northeastern Canada and Greenland (c. 2400 -1800 BCE and c.800-1 BCE) and the Groswaters of Labrador and Nunavik. The Dorset culture spread across the North American Arctic between 500 BCE. C. and the 1500 d. C. The Dorsets were the last great Paleo-Eskimo culture in the Arctic before the eastward migration from present-day Alaska of the Thule, the ancestors of modern Inuit.
The Thule tradition lasted from about 200 B.C. C. until 1600 d. C., arose around the Bering Strait and later covered almost the entire arctic region of North America. The Thule people were the ancestors of the Inuit, who currently live in Alaska, the Northwest Territories, Nunavut, northern Quebec, Labrador, and Greenland.
Europe
For much of European history, the north polar regions remained largely unexplored and their geography conjectural. Pytheas of Massilia recorded an account of a journey north in 325 BCE. C., to a land he called "Eschate Thule", where the sun only set for three hours a day and the water was replaced by a frozen substance "in which no you can walk or navigate". He was probably describing icebergs, while & # 34;Thule & # 34; it was probably Norway, although the Faroe Islands or Shetland have also been suggested.
Climate
The Arctic Ocean is under a polar climate characterized by persistent cold and relatively narrow annual temperature ranges. Winters are characterized by polar night, extreme cold, frequent low-level temperature inversions, and stable weather conditions. Cyclones are common only on the Atlantic side. Summers are characterized by continuous daylight (sun midnight) and the air temperature can rise slightly above 0 °C. Cyclones are more frequent in summer and can bring rain or snow. It is cloudy throughout the year, with average cloud cover ranging from 60% in winter to more than 80% in summer.
The density of seawater, unlike freshwater, increases as it approaches freezing point and therefore tends to sink. In general, the upper 100-150 m of ocean water needs to cool to freezing point for sea ice to form.
The climate of the Arctic region has varied significantly during Earth's history. During the Paleocene-Eocene thermal maximum 55 million years ago, when the global climate warmed by about 5 to 8 °C, the region reached a temperature annual average of 10 to 20 °C. The surface waters of the northernmost Arctic Ocean warmed, at least seasonally, enough to support life forms (the dinoflagellates Apectodinium augustum) that require temperatures above 22 °C. Currently, the arctic region is warming twice as fast as the rest of the planet.
Oceanography
Due to its relative isolation from other oceans, the Arctic Ocean has a uniquely complex system of water flow. It resembles some hydrological features of the Mediterranean Sea, referring to its deep waters that have limited communication through the Fram Strait with the Atlantic basin, "where the circulation is dominated by thermohaline forcing". The Arctic Ocean has a total volume of 18.07 × 106 km³, equivalent to about 1.3% of the world ocean. The mean surface circulation is predominantly cyclonic on the Eurasian side and anticyclonic in the Canadian basin.
Currents
Water enters from the Pacific and Atlantic oceans and can be divided into three unique water masses. The deepest body of water is called Arctic Bottom Water and begins at around 900 m depth. It is made up of the densest water in the world's ocean and It has two main sources: Arctic shelf water and the deep waters of the Greenland Sea. The water in the shelf region that begins when the inflow from the Pacific passes through the Bering Strait strait at an average rate of 0.8 Sverdrups and reaches the Chukotka Sea. During winter, cold winds from Alaska blow over the Chukotka Sea, freezing the surface water and pushing this newly formed ice out into the Pacific. The speed of ice drift is about 1 to 4 cm/s. This process leaves dense, salty water in the sea that sinks onto the continental shelf. in the western Arctic Ocean and create a halocline.
This water meets the deep water of the Greenland Sea, which forms during the passage of winter storms. As temperatures cool dramatically in winter, ice forms, and intense vertical convection allows water to become dense enough to sink beneath the warm saline water below. Arctic bottom water is critically important because of its outflow, which contributes to the formation of the Atlantic deep water. The overturning of this water plays a key role in global circulation and climate moderation.
In the depth range of 150 to 900 m is a body of water called Atlantic water. The influx of the North Atlantic Current enters through the Fram Strait, cooling and sinking to form the deeper layer of the halocline, where it circles the Arctic basin in a counterclockwise direction. This is the highest volumetric inflow to the Arctic Ocean, equal to about 10 times the inflow from the Pacific, and creates the Arctic Ocean Boundary Current. It flows slowly, at about 0.02 m/s. Atlantic water has the same salinity as Arctic bottom water, but is much warmer (up to 31°C). In fact, this body of water is actually warmer than surface water and remains submerged only because of salinity's role in density. When the water reaches the basin, strong winds push it into a large circular current called Beaufort oceanic gyre. The water in Beaufort is much less saline than the Chukotka Sea due to the inflow of large Canadian and Siberian rivers.
The final defined body of water in the Arctic Ocean is called Arctic surface water and lies in the depth range of 150 to 200 m. The most important feature of this body of water is a section called the subterranean layer. It is a product of Atlantic water entering through canyons and undergoing intense mixing on the Siberian shelf. As it entrains, it cools and acts as a heat shield for the surface layer. This insulation prevents the warm water from the Atlantic from melting the ice on the surface. In addition, this water forms the fastest currents in the Arctic, with a speed of about 0.3 to 0.6 m/s. Complementing the water from In the canyons, some Pacific water that does not sink to the shelf region after passing through the Bering Strait also contributes to this water body.
Waters originating from the Pacific and the Atlantic exit through the Fram Strait between Greenland and the island of Svalbard, which is approximately 2700 m deep and 350 km wide. This outlet is approximately 9 Sv. The width of the Fram Strait is what allows both entry and exit on the Atlantic side of the Arctic Ocean. Because of this, it is influenced by the Coriolis force, which concentrates the outflow to the East Greenland Current on the western side and the inflow to the Norway Current on the eastern side. along the west coast of Greenland and the Hudson Strait (at 1-2 Sv), providing nutrients to the Canadian archipelago.
Influence of ice masses
As noted, the process of ice formation and movement is a key factor in the circulation of the Arctic Ocean and the formation of water masses. With this dependency, the Arctic Ocean experiences variations due to seasonal changes in sea ice cover. The movement of sea ice is the result of the force of the wind, which is related to a series of weather conditions that the Arctic experiences throughout the year. For example, the Beaufort High, an extension of the Siberian High, is a pressure system that drives the anticyclonic movement of the Beaufort Gyre. During the summer, this area of high pressure moves closer to its Siberian sides. and Canadian. In addition, there is a pressure ridge at sea level over Greenland that drives strong northerly winds through the Fram Strait, making it easier to export ice. In the summer, the pressure contrast is lower, producing weaker winds. A final example of seasonal pressure system movement is the low pressure system that exists over the Nordic and Barents seas. It is an extension of the Icelandic depression, which creates a cyclonic ocean circulation in this area. The depression moves toward the center over the North Pole in the summer. All these variations in the Arctic contribute to the ice drift reaching its weakest point during the summer months. There is also evidence that the drift is associated with the phase of the Arctic Oscillation and the Atlantic Multidecadal Oscillation.
Biology
There are about four hundred animal species in this area. Of these, the best known is the polar bear, the largest carnivore in the area. It reaches a weight of 800 kg and feeds on seals and fish, although if it fails to catch them it can momentarily replace them with mosses and lichens.
Six species of seals inhabit this site, though their numbers have been decreasing since the 19th century due to their natural predator, the polar bear, and the indiscriminate hunting to which it was subjected by man due to its precious skin and fat. Another typical inhabitant of the area is the whale, equally threatened and currently protected from indiscriminate capture.
Due to the pronounced seasonality of 2–6 months of midnight sun and polar night in the Arctic Ocean, primary production of photosynthesizing organisms such as ice algae and phytoplankton is limited to the spring and summer months. Important consumers of autotrophs in the central Arctic Ocean and adjacent shelf seas include zooplankton, especially copepods (Calanus finmarchicus, Calanus glacialis and Calanus finmarchicus. hyperboreus) and euphausiids, as well as ice-associated fauna (such as amphipods). These form an important link between primary producers and higher trophic levels. The composition of the higher trophic levels in the Arctic Ocean varies by region (Atlantic side vs. Pacific side) and with sea ice cover. Secondary consumers of the Barents Sea, an Atlantic-influenced Arctic shelf sea, are mainly subarctic species, such as herring, cod, and capelin. In the ice-covered regions of the central Arctic Ocean, polar cod are a predator of primary consumers.
Environmental situation
The polar ice pack is thinning, and in many years there will be a seasonal hole in the ozone layer. Reducing the ice surface in the Arctic Ocean lowers the mean albedo of the planet, possibly resulting in global warming in a positive feedback mechanism. Research shows that the Arctic may become ice-free for the first time in the history of humanity between the years 2013 and 2040. Many scientists are currently concerned about warming temperatures in the Arctic, because they could cause large amounts of fresh melt water to enter the North Atlantic, possibly disturbing current patterns. global oceans. Potentially drastic changes in Earth's climate can occur afterwards.
Researchers predict that, in no more than fifty years, the Arctic Ocean will be perfectly navigable during the summer. of high temperatures is increasing. During the past years, the melting of the ice cap has been observed and, in August 2004, American scientists sailing on a ship and a Russian one, denounced the existence of a lagoon at the North Pole, which could not be confirmed by satellite images., but that in no way surprised the scientific community, who have been warning about the danger of global warming.
It is known, then, that the thickness of the ice sheet of the Arctic Ocean has decreased by 40% during the past fifty years and the results indicate that if this continues, the melting of the ice will be faster each time, culminating with the disappearance of these during the summer, with serious consequences for the ecological balance of the area and for the habitat of certain species, such as the polar bear that needs these ice sheets to survive and hunt for food.
Other environmental concerns relate to radioactive contamination of the Arctic Ocean by, for example, Russian radioactive waste in the Kara Sea and Cold War-era nuclear tests in places like Novaya Zemlya.
Natural resources
Note: No territorial claims are shown from other countries.
The melting of the Arctic opens new possibilities to exploit its natural resources. The Arctic seabed contains 25 percent of the world's oil and natural gas reserves. Also tin, manganese, gold, nickel, lead and platinum are present in significant quantities. For this reason, and added to the geostrategic importance, on August 2, 2007, two Russian Mir bathyscaphes made a dive in the Arctic Ocean, at the North Pole, and installed a Russian flag in the background, as well as a capsule with a message. for generations to come. The Mirs collected evidence to prove that the Lomonosov and Mendeleev underwater ridges are the natural extension of Russia's continental shelf, a hypothesis that, if confirmed, would allow Russia to claim exclusive rights to exploit mineral resources in this area in the future..
Natural hazards
Occasionally islands of ice break up off the northern part of Ellesmere Island, and icebergs form from glaciers off the west coast of Greenland and extreme northeast Canada. Permafrost is found on most of the islands. The ocean is virtually closed by ice from October to June, and ships navigating it are threatened with ice cover from October to May. Before the arrival of modern icebreakers, ships sailing into the Arctic Ocean risked to being trapped or crushed by ice floes (although the SS Baychimo wandered the Arctic Ocean unattended for decades despite these risks).