|
Ice Cover
Sea ice arises as seawater freezes. Because ice is less dense than water, it floats on the ocean's surface (as does fresh water ice, which has an even lower density). Sea ice covers about 7% of the Earth's surface and about 12% of the world's oceans. Much of the world's sea ice is enclosed within the polar ice packs in the Earth's polar regions: the Arctic ice pack of the Arctic Ocean and the Antarctic ice pack of the Southern Ocean. Polar packs undergo a significant yearly cycling in surface extent, a natural process upon which depends the Arctic ecology, including the ocean's ecosystems. Due to the action of winds, currents and temperature fluctuations, sea ice is very dynamic, leading to a wide variety of ice types and features. Sea ice may be contrasted with icebergs, which are chunks of ice shelves or glaciers that calve into the ocean. Depending on location, sea ice expanses may also incorporate icebergs. General features and dynamics Sea ice does not simply grow an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Ice
The Arctic ( or ) is a polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenland), Finland, Iceland, Norway, Russia ( Murmansk, Siberia, Nenets Okrug, Novaya Zemlya), Sweden and the United States (Alaska). Land within the Arctic region has seasonally varying snow and ice cover, with predominantly treeless permafrost (permanently frozen underground ice) containing tundra. Arctic seas contain seasonal sea ice in many places. The Arctic region is a unique area among Earth's ecosystems. The cultures in the region and the Arctic indigenous peoples have adapted to its cold and extreme conditions. Life in the Arctic includes zooplankton and phytoplankton, fish and marine mammals, birds, land animals, plants and human societies. Arctic land is bordered by the subarctic. Definition and etymology The word Arctic comes from the Greek word (''ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fast Ice
Fast ice (also called ''land-fast ice'', ''landfast ice'', and ''shore-fast ice'') is sea ice that is "fastened" to the coastline, to the sea floor along shoals or to grounded icebergs.Leppäranta, M. 2011. The Drift of Sea Ice. Berlin: Springer-Verlag. Fast ice may either grow in place from the sea water or by freezing pieces of drifting ice to the shore or other anchor sites.Kovacs, A.and M. Mellor. 1974. "Sea ice morphology and ice as a geologic agent in the Southern Beaufort Sea." pp. 113-164, in: ''The Coast and Shelf of the Beaufort Sea'', J.C. Reed and J.E. Sater (Eds.), Arlington, Va.: U.S.A. Unlike drift (or pack) ice, fast ice does not move with currents and winds. The width (and the presence) of this ice zone is usually seasonal and depends on ice thickness, topography of the sea floor and islands. It ranges from a few meters to several hundred kilometers. Seaward expansion is a function of a number of factors, notably water depth, shoreline protection, time of y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coriolis Effect
In physics, the Coriolis force is an inertial or fictitious force that acts on objects in motion within a frame of reference that rotates with respect to an inertial frame. In a reference frame with clockwise rotation, the force acts to the left of the motion of the object. In one with anticlockwise (or counterclockwise) rotation, the force acts to the right. Deflection of an object due to the Coriolis force is called the Coriolis effect. Though recognized previously by others, the mathematical expression for the Coriolis force appeared in an 1835 paper by French scientist Gaspard-Gustave de Coriolis, in connection with the theory of water wheels. Early in the 20th century, the term ''Coriolis force'' began to be used in connection with meteorology. Newton's laws of motion describe the motion of an object in an inertial (non-accelerating) frame of reference. When Newton's laws are transformed to a rotating frame of reference, the Coriolis and centrifugal accelerations appe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drift Ice
Drift ice, also called brash ice, is sea ice that is not attached to the shoreline or any other fixed object (shoals, grounded icebergs, etc.).Leppäranta, M. 2011. The Drift of Sea Ice. Berlin: Springer-Verlag. Unlike fast ice, which is "fastened" to a fixed object, drift ice is carried along by winds and sea currents, hence its name. When drift ice is driven together into a large single mass (>70% coverage), it is called pack ice. Wind and currents can pile up that ice to form ridges up to tens of metres in thickness. These represent a challenge for icebreakers and offshore structures operating in cold oceans and seas. Drift ice consists of ice floes, individual pieces of sea ice or more across. Floes are classified according to size: ''small'' – to ; ''medium'' – to ; ''big'' – to ; ''vast'' – to ; and ''giant'' – more than . Drift ice affects: * Security of navigation * Climatic impact (see Polar ice packs) * Geological impact * Biosphere influence (see Ecol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctic
The Antarctic ( or , American English also or ; commonly ) is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau and other island territories located on the Antarctic Plate or south of the Antarctic Convergence. The Antarctic region includes the ice shelves, waters, and all the island territories in the Southern Ocean situated south of the Antarctic Convergence, a zone approximately wide varying in latitude seasonally. The region covers some 20 percent of the Southern Hemisphere, of which 5.5 percent (14 million km2) is the surface area of the Antarctica continent itself. All of the land and ice shelves south of 60°S latitude are administered under the Antarctic Treaty System. Biogeographically, the Antarctic realm is one of eight biogeographic realms of Earth's land surface. Geography As defined by the Antarctic Treaty System, the Antarctic r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic
The Arctic ( or ) is a polar regions of Earth, polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenland), Finland, Iceland, Norway, Russia (Murmansk Oblast, Murmansk, Siberia, Nenets Autonomous Okrug, Nenets Okrug, Novaya Zemlya), Sweden and the United States (Alaska). Land within the Arctic region has seasonally varying snow and sea ice, ice cover, with predominantly treeless permafrost (permanently frozen underground ice) containing tundra. Arctic seas contain seasonal sea ice in many places. The Arctic region is a unique area among Earth's ecosystems. The cultures in the region and the Arctic indigenous peoples have adapted to its cold and extreme conditions. Life in the Arctic includes zooplankton and phytoplankton, fish and marine mammals, birds, land animals, plants and human societies. Arctic land is bordered by the subarctic. De ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Guardian
''The Guardian'' is a British daily newspaper. It was founded in 1821 as ''The Manchester Guardian'', and changed its name in 1959. Along with its sister papers ''The Observer'' and ''The Guardian Weekly'', ''The Guardian'' is part of the Guardian Media Group, owned by the Scott Trust. The trust was created in 1936 to "secure the financial and editorial independence of ''The Guardian'' in perpetuity and to safeguard the journalistic freedom and liberal values of ''The Guardian'' free from commercial or political interference". The trust was converted into a limited company in 2008, with a constitution written so as to maintain for ''The Guardian'' the same protections as were built into the structure of the Scott Trust by its creators. Profits are reinvested in journalism rather than distributed to owners or shareholders. It is considered a newspaper of record in the UK. The editor-in-chief Katharine Viner succeeded Alan Rusbridger in 2015. Since 2018, the paper's main news ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Eggs
Ice eggs, or ice balls, are a rare phenomenon caused by a process in which small pieces of sea ice in open water are rolled over by wind and currents in freezing conditions and grow into spheroid pieces of ice. They may collect into heaps of balls or 'eggs' on beaches. The gentle churn of water, blown by a suitably stiff breeze makes concentric layers of ice form on a seed particle that then grows into the floating ball as it rolls through the freezing currents. Given enough time, the frozen balls can grow to become boulder size. In 2016, giant snowballs washed up on a beach in Siberia, some measuring a metre (about 3 feet) across. An ice specialist from the Finnish Meteorological Institute has been quoted as saying ice balls are rare but not unprecedented, and occur about once a year on the Finnish coastline as conditions allow. They also appear on the Great Lakes, American Great Lakes where they are called Ice balls. See also * Yukimarimo - Wind blown balls of fine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pancake Ice
Pancake ice is a form of sea ice that consists of round pieces of ice with diameters ranging from 30 centimetres (12 in) to 3 metres (9.8 ft) and thicknesses up to 10 centimetres (3.9 inches), depending on the local conditions. It forms as a result of wave action on slush or ice rind. Characteristics Pancake ice features elevated rims formed by piling of frazil ice or slush onto the edges of pancakes when they collide, both due to random bumping into each other and because of periodic compressions at wave troughs. These rims are the first indication of the onset of the formation of the pancake ice from less consolidated forms of ice. Formation Pancake ice forms in conditions of high wave activity, in contrast to other types of sea ice formed under calm conditions. Pancake ice can form in two processes: (1) on water covered to some degree in slush, shuga or grease ice, or (2) from breaking of ice rind, nilas or even gray ice in agitated conditions. If the waves are strong eno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grease Ice
Grease ice is a very thin, soupy layer of frazil crystals clumped together, which makes the ocean surface resemble an oil slick. Grease ice is the second stage in the formation of solid sea ice after ice floes and then frazil ice. New sea ice formation takes place throughout the winter in the Arctic. The first ice that forms in a polynya are loose ice crystals called frazil ice. If the level of turbulence is sufficient, the frazil ice will be mixed down into the upper layer and form a surface layer of grease ice. The term ‘grease ice’ follows World Meteorological Organization nomenclature. Grease ice differs from ‘slush’, where slush is similarly created by snow falling into the top layer of an ocean basin, river, or lake. The two terms are related due to the process of ice crystals being blown into a polynya which can be the initiation of the grease ice layer, given a minimum level of mixing and cooling of the ocean surface. Formation When the water surface begin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slush
Slush, also called slush ice, is a slurry mixture of small ice crystals (e.g., snow) and liquid water. In the natural environment, slush forms when ice or snow melts or during mixed precipitation. This often mixes with dirt and other pollutants on the surface, resulting in a gray or muddy brown color. Often, solid ice or snow can block the drainage of fluid water from slushy areas, so slush often goes through multiple freeze/thaw cycles before being able to completely drain and disappear. In areas where road salt is used to clear roadways, slush forms at lower temperatures in salted areas than it would ordinarily. This can produce a number of different consistencies over the same geographical area with scattered salted areas covered with slush and others covered with frozen precipitation . Hazards Because slush behaves like a non-Newtonian fluid, which means it behaves like a mostly solid mass until its inner shear forces rise beyond a specific threshold and beyond can ver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> Arctic Ice")
._05.jpg "Click for more on -> Ice Eggs")
