Iceberg

Iceberg

Overview


An iceberg is a large piece of ice from freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...

 that has broken off from a snow-formed glacier
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

 or ice shelf
Ice shelf
An ice shelf is a thick, floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface. Ice shelves are only found in Antarctica, Greenland and Canada. The boundary between the floating ice shelf and the grounded ice that feeds it is called...

 and is floating in open water. It may subsequently become frozen into pack ice. Alternatively, it may come to rest on the seabed in shallower water, causing ice scour
Ice scour
Ice scour is a geological term for long, narrow ditches in a seabed, created by the collision of fast ice and pack ice and the grounding of icebergs. Synonyms include ice gouging, ice ploughing, ice score and keel scour...

 (also known as ice gouging) or becoming an ice island.


The word "iceberg" is a partial loan translation from Dutch
Dutch language
Dutch is a West Germanic language and the native language of the majority of the population of the Netherlands, Belgium, and Suriname, the three member states of the Dutch Language Union. Most speakers live in the European Union, where it is a first language for about 23 million and a second...

 ijsberg, literally meaning ice mountain, cognate to Danish
Danish language
Danish is a North Germanic language spoken by around six million people, principally in the country of Denmark. It is also spoken by 50,000 Germans of Danish ethnicity in the northern parts of Schleswig-Holstein, Germany, where it holds the status of minority language...

 Isbjerg, German
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....

 Eisberg, Low Saxon Iesbarg, Swedish
Swedish language
Swedish is a North Germanic language, spoken by approximately 10 million people, predominantly in Sweden and parts of Finland, especially along its coast and on the Åland islands. It is largely mutually intelligible with Norwegian and Danish...

 Isberg and Norwegian
Norwegian language
Norwegian is a North Germanic language spoken primarily in Norway, where it is the official language. Together with Swedish and Danish, Norwegian forms a continuum of more or less mutually intelligible local and regional variants .These Scandinavian languages together with the Faroese language...

 Isfjell.

Because the density
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...

 of pure ice is about 920 kg/m³, and that of sea water about 1025 kg/m³, typically only one-ninth of the volume of an iceberg is above water.
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Encyclopedia


An iceberg is a large piece of ice from freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...

 that has broken off from a snow-formed glacier
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

 or ice shelf
Ice shelf
An ice shelf is a thick, floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface. Ice shelves are only found in Antarctica, Greenland and Canada. The boundary between the floating ice shelf and the grounded ice that feeds it is called...

 and is floating in open water. It may subsequently become frozen into pack ice. Alternatively, it may come to rest on the seabed in shallower water, causing ice scour
Ice scour
Ice scour is a geological term for long, narrow ditches in a seabed, created by the collision of fast ice and pack ice and the grounding of icebergs. Synonyms include ice gouging, ice ploughing, ice score and keel scour...

 (also known as ice gouging) or becoming an ice island.

Etymology



The word "iceberg" is a partial loan translation from Dutch
Dutch language
Dutch is a West Germanic language and the native language of the majority of the population of the Netherlands, Belgium, and Suriname, the three member states of the Dutch Language Union. Most speakers live in the European Union, where it is a first language for about 23 million and a second...

 ijsberg, literally meaning ice mountain, cognate to Danish
Danish language
Danish is a North Germanic language spoken by around six million people, principally in the country of Denmark. It is also spoken by 50,000 Germans of Danish ethnicity in the northern parts of Schleswig-Holstein, Germany, where it holds the status of minority language...

 Isbjerg, German
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....

 Eisberg, Low Saxon Iesbarg, Swedish
Swedish language
Swedish is a North Germanic language, spoken by approximately 10 million people, predominantly in Sweden and parts of Finland, especially along its coast and on the Åland islands. It is largely mutually intelligible with Norwegian and Danish...

 Isberg and Norwegian
Norwegian language
Norwegian is a North Germanic language spoken primarily in Norway, where it is the official language. Together with Swedish and Danish, Norwegian forms a continuum of more or less mutually intelligible local and regional variants .These Scandinavian languages together with the Faroese language...

 Isfjell.

Overview


Because the density
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...

 of pure ice is about 920 kg/m³, and that of sea water about 1025 kg/m³, typically only one-ninth of the volume of an iceberg is above water. The shape of the underwater portion can be difficult to judge by looking at the portion above the surface. This has led to the expression "tip of the iceberg", for a problem or difficulty that is only a small manifestation of a larger problem.

Icebergs generally range from 1 to 75 m (3.3 to 246.1 ft) above sea level and weigh 100000 to 200000 MT (110,231.1 to 220,462.3 ST). The largest known iceberg in the North Atlantic was 168 metres (551.2 ft) above sea level, reported by the USCG icebreaker East Wind in 1958, making it the height of a 55-storey building. These icebergs originate from the glaciers of western Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...

, and may have an interior temperature of -15 C.

Though usually confined by winds and currents to move close to the coast, the largest icebergs recorded have been calved
Ice calving
Ice calving, also known as glacier calving or iceberg calving, is a form of ice ablation or ice disruption. It is the sudden release and breaking away of a mass of ice from a glacier, iceberg, ice front, ice shelf, or crevasse...

, or broken off, from the Ross Ice Shelf
Ross Ice Shelf
The Ross Ice Shelf is the largest ice shelf of Antarctica . It is several hundred metres thick. The nearly vertical ice front to the open sea is more than 600 km long, and between 15 and 50 metres high above the water surface...

 of Antarctica. Iceberg B-15
Iceberg B-15
Iceberg B-15 is one of the world's largest recorded icebergs. It measured around 295 km long and 37 km wide , with a surface area of 11,000 km² larger than the island of Jamaica. The mass was estimated around three billion tonnes...

, photographed by satellite in 2000, measured 295 by, with a surface area of 11000 square kilometre. The mass was estimated around three billion tonnes. The largest iceberg on record was an Antarctic tabular iceberg of over 31000 square kilometre [335 by] sighted 150 miles (241.4 km) west of Scott Island
Scott Island
Scott Island is a small uninhabited island of volcanic origin in the Ross Sea, Southern Ocean, northeast of Cape Adare, the northeastern extremity of Victoria Land, Antarctica. It is long north-south, and between and wide, reaching a height of and covering an area of...

, in the South Pacific Ocean, by the USS Glacier on November 12, 1956. This iceberg was larger than Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

.

When an iceberg melts, it makes a fizzing sound called "Bergie Seltzer". This sound is made when compressed air bubbles trapped in the iceberg pop. The bubbles come from air trapped in snow layers that later became glacial ice.

Size


Names for various sizes of iceberg are not universal, but usually follow a similar pattern. The size classification in the table below is used by the International Ice Patrol
International Ice Patrol
The International Ice Patrol is an organization with the purpose of monitoring the presence of icebergs in the Atlantic and Arctic Oceans and reporting their movements for safety purposes. It is operated by United States Coast Guard but is funded by the 13 nations interested in trans-Atlantic...

:
Size Category Height Length
Growler Less than 1 metres (3.3 ft) Less than 5 metres (16.4 ft)
Bergy Bit 1–5 m (3.3–16.4 ft) 5 –
Small 5 – 15 –
Medium 15 – 60 –
Large 45 – 120 –
Very Large Over 75 metres (246.1 ft) Over 200 metres (656.2 ft)

Recent large icebergs

  • Iceberg B-15
    Iceberg B-15
    Iceberg B-15 is one of the world's largest recorded icebergs. It measured around 295 km long and 37 km wide , with a surface area of 11,000 km² larger than the island of Jamaica. The mass was estimated around three billion tonnes...

     11000 km² (4,247.1 sq mi), 2000
  • Iceberg A-38, about 6900 km² (2,664.1 sq mi), 1998
  • Iceberg B-15A, 3100 km² (1,196.9 sq mi), broke off 2003
  • Iceberg C-19
    Iceberg C-19
    Iceberg C-19 is an iceberg that calved from the Ross Ice Shelf on May 2002 on a fissure scientists had been watching since the 1980s. After that the Ross Ice Shelf returned to the size it was in 1911, when it was mapped by Robert F. Scott’s party. It was the second-largest iceberg to calve in the...

    , 5500 km² (2,123.6 sq mi), 2002
  • Iceberg B-9
    Iceberg B-9
    Iceberg B-9 154 km by 35 km calved away from Antarctica, from the sector east of Roosevelt Island, neighbouring the Bay of Whales and immediately east of the calving site of Iceberg B-15. It carried away Little America V....

    , 5390 km² (2,081.1 sq mi), 1987
  • Iceberg D-16
    Iceberg D-16
    Iceberg D-16 is a city-sized iceberg near Antarctica, discovered on March 26, 2006 by the National Ice Center using satellite imagery from the Defense Meteorological Satellite Program...

    , 120 sq mi (310.8 km²), 2006
  • Ice sheet, 100 sq mi (259 km²), broken off of Petermann Glacier
    Petermann glacier
    Petermann Glacier is a large glacier located in North-West Greenland to the east of Nares Strait. It connects the Greenland ice sheet to the Arctic Ocean near 81 degrees north latitude. The tidewater glacier consists of a long and wide floating ice tongue whose thickness changes from about at...

     in northern Greenland
    Greenland
    Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...

     on Aug 5, 2010, considered to be largest Arctic iceberg since 1962. About a month later, this iceberg split into two pieces upon crashing into Joe Island in the Nares Strait
    Nares Strait
    Nares Strait is a waterway between Ellesmere Island and Greenland that is the northern part of Baffin Bay where it meets the Lincoln Sea. From south to north, the strait includes Smith Sound, Kane Basin, Kennedy Channel, Hall Basin and Robeson Channel...

     next to Greenland. In June 2011, large fragments of the Petermann Ice Islands were observed off the Labrador coast.
  • Iceberg B-17B
    Iceberg B-17B
    Iceberg B-17B is an iceberg twice the size of Manhattan, floating in the southern ocean approximately off the coast of Western Australia. Iceberg B-17B measures approximately and calved off the Ross Ice Shelf in 1999....

     140 km² (54.1 sq mi), 1999, shipping
    Sea lane
    A sea lane or shipping lane is a regularly used route for ocean-going and Great Lakes vessels. In the time of sailing ships they were not only determined by the distribution of land masses but also the prevailing winds, whose discovery was crucial for the success of long voyages...

     alert issued December 2009

Shape


In addition to size classification, Icebergs can also be classified on the basis of their shape. The two basic types of iceberg forms are tabular and non-tabular. Tabular icebergs have steep sides and a flat top, much like a plateau
Plateau
In geology and earth science, a plateau , also called a high plain or tableland, is an area of highland, usually consisting of relatively flat terrain. A highly eroded plateau is called a dissected plateau...

, with a length-to-height ratio of more than 5:1. This type of iceberg can be quite large, as in the case of Pobeda Ice Island
Pobeda Ice Island
Pobeda Ice Island, original Russian name остров Победы , is an ice island in the Mawson Sea. It is located off the coast of Queen Mary Land, Australian Antarctic Territory, East Antarctica...

. Antarctic
Antarctic
The Antarctic is the region around the Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica and the ice shelves, waters and island territories in the Southern Ocean situated south of the Antarctic Convergence...

 icebergs formed by breaking off from an ice shelf
Ice shelf
An ice shelf is a thick, floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface. Ice shelves are only found in Antarctica, Greenland and Canada. The boundary between the floating ice shelf and the grounded ice that feeds it is called...

, such as the Ross Ice Shelf
Ross Ice Shelf
The Ross Ice Shelf is the largest ice shelf of Antarctica . It is several hundred metres thick. The nearly vertical ice front to the open sea is more than 600 km long, and between 15 and 50 metres high above the water surface...

 or Filchner-Ronne Ice Shelf
Filchner-Ronne Ice Shelf
The Filchner-Ronne Ice Shelf, also known as Ronne-Filchner Ice Shelf, is an Antarctic ice shelf bordering the Weddell Sea.-Description:...

, are typically tabular. The largest icebergs in the world are formed this way.
Non-tabular icebergs have different shapes, and include:
  • Dome: An iceberg with a rounded top.
  • Pinnacle: An iceberg with one or more spire
    Spire
    A spire is a tapering conical or pyramidal structure on the top of a building, particularly a church tower. Etymologically, the word is derived from the Old English word spir, meaning a sprout, shoot, or stalk of grass....

    s.
  • Wedge: An iceberg with a steep edge on one side and a slope on the opposite side.
  • Dry-Dock: An iceberg that has eroded
    Erosion
    Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

     to form a slot or channel
    Channel (geography)
    In physical geography, a channel is the physical confine of a river, slough or ocean strait consisting of a bed and banks.A channel is also the natural or human-made deeper course through a reef, sand bar, bay, or any shallow body of water...

    .
  • Blocky: An iceberg with steep, vertical sides and a flat top. It differs from tabular icebergs in that its shape is more like a block than a flat sheet.

Monitoring


Icebergs are monitored worldwide by the U.S. National Ice Center
National Ice Center
The National Ice Center is a tri-agency operational center whose mission is to provide world-wide navigational ice analyses for the armed forces of the United States, allied nations, and U.S...

 (NIC), established in 1995, which produces analyses and forecasts of Arctic
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...

, Antarctic
Antarctic Circle
The Antarctic Circle is one of the five major circles of latitude that mark maps of the Earth. For 2011, it is the parallel of latitude that runs south of the Equator.-Description:...

, Great Lakes
Great Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...

 and Chesapeake Bay
Chesapeake Bay
The Chesapeake Bay is the largest estuary in the United States. It lies off the Atlantic Ocean, surrounded by Maryland and Virginia. The Chesapeake Bay's drainage basin covers in the District of Columbia and parts of six states: New York, Pennsylvania, Delaware, Maryland, Virginia, and West...

 ice conditions. More than 95% of the data used in its sea ice analyses are derived from the remote sensors on polar-orbiting satellites that survey these remote regions of the Earth.

The NIC is the only organization that names and tracks all Antarctic Icebergs. It assigns each iceberg larger than 10 nautical miles (18.5 km) along at least one axis a name composed of a letter indicating its point of origin and a running number. The letters used are as follows:
  • Alongitude
    Longitude
    Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is an angular measurement, usually expressed in degrees, minutes and seconds, and denoted by the Greek letter lambda ....

     0° to 90° W (Bellingshausen Sea
    Bellingshausen Sea
    The Bellingshausen Sea is an area along the west side of the Antarctic Peninsula, west of Alexander Island, east of Cape Flying Fish on Thurston Island, and south of Peter I Island . In the south are, from west to east, Eights Coast, Bryan Coast and English Coast of West Antarctica...

    , Weddell Sea
    Weddell Sea
    The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula. The easternmost point is Cape Norvegia at Princess Martha Coast, Queen Maud Land. To the east of Cape Norvegia is...

    )
  • B – longitude 90° W to 180° (Amundsen Sea
    Amundsen Sea
    The Amundsen Sea is an arm of the Southern Ocean off Marie Byrd Land in western Antarctica. It is bounded by Cape Flying Fish, the northwestern tip of Thurston Island to the east and Cape Dart on Siple Island to the west. East of Cape Flying Fish starts the Bellingshausen Sea. West of Cape Dart is...

    , Eastern Ross Sea
    Ross Sea
    The Ross Sea is a deep bay of the Southern Ocean in Antarctica between Victoria Land and Marie Byrd Land.-Description:The Ross Sea was discovered by James Ross in 1841. In the west of the Ross Sea is Ross Island with the Mt. Erebus volcano, in the east Roosevelt Island. The southern part is covered...

    )
  • C – longitude 90° E to 180° (Western Ross Sea, Wilkes Land
    Wilkes Land
    Wilkes Land is a large district of land in eastern Antarctica, formally claimed by Australia as part of the Australian Antarctic Territory, though the validity of this claim has been placed for the period of the operation of the Antarctic Treaty, to which Australia is a signatory...

    )
  • D – longitude 0° to 90° E (Amery Ice Shelf
    Amery Ice Shelf
    The Amery Ice Shelf is a broad ice shelf in Antarctica at the head of Prydz Bay between the Lars Christensen Coast and Ingrid Christensen Coast. It is part of Mac. Robertson Land. The name "Cape Amery" was applied to a coastal angle mapped on February 11, 1931 by the British Australian New Zealand...

    , Eastern Weddell Sea)


Iceberg B15 calved from the Ross Ice Shelf
Ross Ice Shelf
The Ross Ice Shelf is the largest ice shelf of Antarctica . It is several hundred metres thick. The nearly vertical ice front to the open sea is more than 600 km long, and between 15 and 50 metres high above the water surface...

 in 2000 and initially had an area of 11000 square kilometre. It broke apart in November 2002. The largest remaining piece of it, Iceberg B-15A, with an area of 3000 square kilometre, was still the largest iceberg on Earth until it ran aground and split into several pieces October 27, 2005. It has been determined that the cause of the breakup was an ocean swell generated by an Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...

n storm 6 days earlier and 13500 kilometres (8,388.5 mi) away.

History


In the 20th century, several scientific bodies were established to study and monitor the icebergs. The International Ice Patrol
International Ice Patrol
The International Ice Patrol is an organization with the purpose of monitoring the presence of icebergs in the Atlantic and Arctic Oceans and reporting their movements for safety purposes. It is operated by United States Coast Guard but is funded by the 13 nations interested in trans-Atlantic...

, formed in 1914 in response to the Titanic disaster, monitors iceberg dangers near the Grand Banks
Grand Banks
The Grand Banks of Newfoundland are a group of underwater plateaus southeast of Newfoundland on the North American continental shelf. These areas are relatively shallow, ranging from in depth. The cold Labrador Current mixes with the warm waters of the Gulf Stream here.The mixing of these waters...

 of Newfoundland and provides the "limits of all known ice" in that vicinity to the maritime community.

Technology history


Before April 1912 there was no system in place to track icebergs to guard ships against collisions. The sinking of the RMS Titanic, which caused the deaths of 1,523 of its 2,228 passengers, created the demand for a system to observe icebergs. For the remainder of the ice season of that year, the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 patrolled the waters and monitored ice flow. In November 1913, the International Conference on the Safety of Life at Sea met in London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

 to devise a more permanent system of observing icebergs. Within three months the participating maritime nations had formed the International Ice Patrol
International Ice Patrol
The International Ice Patrol is an organization with the purpose of monitoring the presence of icebergs in the Atlantic and Arctic Oceans and reporting their movements for safety purposes. It is operated by United States Coast Guard but is funded by the 13 nations interested in trans-Atlantic...

 (IIP). The goal of the IIP was to collect data on meteorology
Meteorology
Meteorology is the interdisciplinary scientific study of the atmosphere. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 18th century. The 19th century saw breakthroughs occur after observing networks developed across several countries...

 and oceanography
Oceanography
Oceanography , also called oceanology or marine science, is the branch of Earth science that studies the ocean...

 in order to measure currents, ice-flow, ocean temperature, and salinity levels. They published their first records in 1921, which allowed for a year-by-year comparison of iceberg movement.

New technologies monitor icebergs. Aerial surveillance of the seas in the early 1930s allowed for the development of charter systems that could accurately detail the ocean currents and iceberg locations. In 1945, experiments tested the effectiveness of radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

 in detecting icebergs. A decade later, oceanographic monitoring outposts were established for the purpose of collecting data; these outposts continue to serve in environmental study. A computer was first installed on a ship for the purpose of oceanographic monitoring in 1964, which allowed for a faster evaluation of data. By the 1970s, icebreaking ships were equipped with automatic transmissions of satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

 photographs of ice in Antarctica. Systems for optical satellites had been developed, but were still limited by weather conditions. In the 1980s, drifting buoy
Buoy
A buoy is a floating device that can have many different purposes. It can be anchored or allowed to drift. The word, of Old French or Middle Dutch origin, is now most commonly in UK English, although some orthoepists have traditionally prescribed the pronunciation...

s were used in Antarctic waters for oceanographic and climate research. They are equipped with sensors that measure ocean temperature and currents. Side-Looking Airborne Radar (SLAR) made it possible to acquire images regardless of weather conditions. On November 4, 1995, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 launched RADARSAT-1
RADARSAT-1
Radarsat-1 is Canada's first commercial Earth observation satellite.-Mission:It was launched at 14h22 UTC on November 4, 1995 from Vandenberg AFB in California, into a sun-synchronous orbit above the Earth with an altitude of 798 kilometers and inclination of 98.6 degrees...

. Developed by the Canadian Space Agency, it provides images of Earth for both scientific and commercial purposes. This system was the first to use Synthetic Aperture Radar
Synthetic aperture radar
Synthetic-aperture radar is a form of radar whose defining characteristic is its use of relative motion between an antenna and its target region to provide distinctive long-term coherent-signal variations that are exploited to obtain finer spatial resolution than is possible with conventional...

 (SAR), which sends microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...

 energy to the ocean surface and records the reflections to track icebergs. The European Space Agency
European Space Agency
The European Space Agency , established in 1975, is an intergovernmental organisation dedicated to the exploration of space, currently with 18 member states...

 launched ENVISAT
Envisat
Envisat is an Earth-observing satellite. It was launched on 1 March 2002 aboard an Ariane 5 from the Guyana Space Centre in Kourou, French Guyana into a Sun synchronous polar orbit at an altitude of...

 on March 1, 2002, an environmental satellite which uses Advanced Synthetic Aperture Radar (ASAR). This can detect changes in surface height accurately. The Canadian Space Agency launched RADARSAT-2
RADARSAT-2
Radarsat-2 is an Earth observation satellite that was successfully launched December 14, 2007 for the Canadian Space Agency by Starsem, using a Soyuz FG launch vehicle, from Kazakhstan's Baikonur Cosmodrome....

 in December in the year of 2007, which uses SAR and multipolarization modes and follows the same orbit
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...

 path as RADARSAT-1.

See also

  • Drift ice station
  • Ice calving
    Ice calving
    Ice calving, also known as glacier calving or iceberg calving, is a form of ice ablation or ice disruption. It is the sudden release and breaking away of a mass of ice from a glacier, iceberg, ice front, ice shelf, or crevasse...

  • Ice drift
    Ice drift
    Ice drift is movement of ice. An important type of ice drift is drift of the sea ice, i.e., of the drift ice. Unless specified otherwise, this article discusses the drift of the sea ice. The direction of the ice drift is the vector sum of the oceanic and atmospheric circulations, i.e., upper ocean...

  • Polar ice cap
    Polar ice cap
    A polar ice cap is a high latitude region of a planet or natural satellite that is covered in ice. There are no requirements with respect to size or composition for a body of ice to be termed a polar ice cap, nor any geological requirement for it to be over land; only that it must be a body of...

  • Polar ice packs
  • Polynya
    Polynya
    A polynya or polynia is an area of open water surrounded by sea ice. It is now used as geographical term for an area of unfrozen sea within the ice pack. It is a loanword from , , which means a natural ice hole, and was adopted in the 19th century by polar explorers to describe navigable...

  • Sea ice
    Sea ice
    Sea ice is largely formed from seawater that freezes. Because the oceans consist of saltwater, this occurs below the freezing point of pure water, at about -1.8 °C ....

  • Shelf ice
    Shelf ice
    Shelf ice can refer to the ice that forms when a portion of a lake surface freezes. It is often then washed upon the shore. This is common within the Great Lakes.-Formation:...


External links