News tagged with ice sheet
Study shows global glaciers, ice caps, shedding billions of tons of mass annually
Earth's glaciers and ice caps outside of the regions of Greenland and Antarctica are shedding roughly 150 billion tons of ice annually, according to a new study led by the University of Colorado Boulder.
Space & Earth / Earth Sciences
Feb 08, 2012 |
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Image: Crack discovered in Pine Island Glacier
(PhysOrg.com) -- In mid-October 2011, NASA scientists working in Antarctica discovered a massive crack across the Pine Island Glacier, a major ice stream that drains the West Antarctic Ice Sheet. Extending ...
Space & Earth / Earth Sciences
Feb 01, 2012 |
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Of orbits and ice ages: Researcher confirms that axis shifts help to propel temperature changes
Though it was first suggested well over a century ago, the hypothesis that changes in Earth’s orientation relative to its orbit influence the growth and decline of ice sheets was only recently tested.
Space & Earth / Earth Sciences
Jan 11, 2012 |
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Ice sheets can expand in a geologic instant, Arctic study shows
(PhysOrg.com) -- A fast-moving glacier on the Greenland Ice Sheet expanded in a geologic instant several millennia ago, growing in response to cooling periods that lasted not much longer than a century, according ...
Space & Earth / Earth Sciences
Dec 14, 2011 |
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Tropical sea temperatures influence melting in Antarctica
Accelerated melting of two fast-moving outlet glaciers that drain Antarctic ice into the Amundsen Sea Embayment is likely the result, in part, of an increase in sea-surface temperatures in the tropical Pacific Ocean, according ...
Space & Earth / Earth Sciences
Dec 06, 2011 |
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Simultaneous ice melt in Antarctic and Arctic
The end of the last ice age and the processes that led to the melting of the northern and southern ice sheets supply basic information on changes in our climate. Although the maximum size of the ice sheet in the northern ...
Space & Earth / Earth Sciences
Dec 02, 2011 |
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Plunge in CO2 put the freeze on Antarctica
Plunge in CO2 put the freeze on AntarcticaAtmospheric carbon dioxide levels plunged by 40% before and during the formation of the Antarctic ice sheet 34 million years ago, according to a new study. The finding helps solv ...
Space & Earth / Earth Sciences
Dec 01, 2011 |
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Taking the pulse of an iceberg -- scientists simulate laser imaging for NASA missions
Monitoring glaciers and ice sheets is complicated work. They move and change shape. They melt.
Nov 29, 2011 |
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Gamburtsev Subglacial Mountains enigma unraveled in East Antarctica
The birth of the Gamburtsev Subglacial Mountains buried beneath the vast East Antarctic Ice Sheet – a puzzle mystifying scientists since their first discovery in 1958 – is finally solved. The remarkably ...
Space & Earth / Earth Sciences
Nov 16, 2011 |
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Antarctic rocks help predict sea levels
Ancient rocks embedded in the West Antarctic ice sheet could help University scientists improve sea level predictions.
Space & Earth / Earth Sciences
Nov 14, 2011 |
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Watching the birth of an iceberg
(PhysOrg.com) -- After discovering an emerging crack that cuts across the floating ice shelf of Pine Island Glacier in Antarctica, NASA's Operation IceBridge has flown a follow-up mission and made the first-ever ...
Space & Earth / Earth Sciences
Nov 02, 2011 |
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Extreme melting on Greenland ice sheet, team reports
The Greenland ice sheet can experience extreme melting even when temperatures don't hit record highs, according to a new analysis by Dr. Marco Tedesco, assistant professor in the Department of Earth and Atmospheric Sciences ...
Space & Earth / Earth Sciences
Oct 25, 2011 |
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CryoSat rocking and rolling
(PhysOrg.com) -- ESA’s ice satellite is rolling left and right in orbit to help it continue its precise measurements of the vast ice sheets that blanket Greenland and Antarctica.
Space & Earth / Earth Sciences
Oct 18, 2011 |
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NASA continues critical survey of Antarctica's changing ice
Scientists with NASA's Operation IceBridge airborne research campaign began the mission's third year of surveys this week over the changing ice of Antarctica.
Space & Earth / Earth Sciences
Oct 13, 2011 |
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Engineering team heads to Antarctica to explore hidden lake
Next week a British engineering team heads off to Antarctica for the first stage of an ambitious scientific mission to collect water and sediment samples from a lake buried beneath three kilometres of solid ice. This extraordinary ...
Space & Earth / Earth Sciences
Oct 10, 2011 |
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Ice sheet
An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km² (20,000 mile²). The only current ice sheets are in Antarctica and Greenland; during the last glacial period at Last Glacial Maximum (LGM) the Laurentide ice sheet covered much of Canada and North America, the Weichselian ice sheet covered northern Europe and the Patagonian Ice Sheet covered southern South America.
Ice sheets are bigger than ice shelves or glaciers. Masses of ice covering less than 50,000 km2 are termed an ice cap. An ice cap will typically feed a series of glaciers around its periphery.
Although the surface is cold, the base of an ice sheet is generally warmer due to geothermal heat. In places, melting occurs and the melt-water lubricates the ice sheet so that it flows more rapidly. This process produces fast-flowing channels in the ice sheet — these are ice streams.
The present-day polar ice sheets are relatively young in geological terms. The Antarctic Ice Sheet first formed as a small ice cap (maybe several) in the early Oligocene, but retreating and advancing many times until the Pliocene, when it came to occupy almost all of Antarctica. The Greenland ice sheet did not develop at all until the late Pliocene, but apparently developed very rapidly with the first continental glaciation. This had the unusual effect of allowing fossils of plants that once grew on present-day Greenland to be much better preserved than with the slowly forming Antarctic ice sheet.
For more information about Ice sheet, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
