News tagged with ice sheet
Warming ocean layers will undermine polar ice sheets
Warming of the ocean's subsurface layers will melt underwater portions of the Greenland and Antarctic ice sheets faster than previously thought, according to new University of Arizona-led research. Such melting ...
Space & Earth / Earth Sciences
Jul 03, 2011 |
3.3 / 5 (14) |
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Fossilized pollen reveals climate history of northern Antarctica
A painstaking examination of the first direct and detailed climate record from the continental shelves surrounding Antarctica reveals that the last remnant of Antarctic vegetation existed in a tundra landscape ...
Space & Earth / Earth Sciences
Jun 27, 2011 |
5 / 5 (7) |
7
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New map reveals giant fjords beneath East Antarctic ice sheet
Scientists from the U.S., U.K. and Australia have used ice-penetrating radar to create the first high- resolution topographic map of one of the last uncharted regions of Earth, the Aurora Subglacial Basin, ...
Space & Earth / Earth Sciences
Jun 01, 2011 |
not rated yet |
7
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Climate played big role in Vikings' disappearance from Greenland
The end of the Norse settlements on Greenland likely will remain shrouded in mystery. While there is scant written evidence of the colony's demise in the 14th and early 15th centuries, archaeological remains ...
Other Sciences / Archaeology & Fossils
May 30, 2011 |
4.3 / 5 (7) |
4
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Antarctic sea temperatures cooled in Holocene but now rising: study
(PhysOrg.com) -- A new study of an ocean sediment core taken from deep water off the coast of the western Antarctic Peninsula is beginning to fill in some of the gaps in our knowledge of climate variability ...
Space & Earth / Earth Sciences
Feb 10, 2011 |
4.2 / 5 (18) |
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Geobiologists uncover links between ancient climate change and mass extinction
About 450 million years ago, Earth suffered the second-largest mass extinction in its history—the Late Ordovician mass extinction, during which more than 75 percent of marine species died. Exactly what ...
Space & Earth / Earth Sciences
Jan 27, 2011 |
4.2 / 5 (19) |
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Climate change to continue to year 3000 in best case scenarios: research
New research indicates the impact of rising CO2 levels in the Earth's atmosphere will cause unstoppable effects to the climate for at least the next 1000 years, causing researchers to estimate a collapse of the West Antar ...
Space & Earth / Earth Sciences
Jan 09, 2011 |
2.8 / 5 (58) |
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Strange Martian Spirals Explained
Almost 40 years ago, NASA's Mariner 9 spacecraft relayed to Earth the first video images of Mars' northern polar ice cap, revealing a strange pattern of spiral swirls that has puzzled scientists ever since. ...
Space & Earth / Space Exploration
Jun 16, 2010 |
4.4 / 5 (12) |
5
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Ice sheet melt identified as trigger of Big Freeze
The main cause of a rapid global cooling period, known as the Big Freeze or Younger Dryas - which occurred nearly 13,000 years ago - has been identified thanks to the help of an academic at the University of Sheffield.
Space & Earth / Earth Sciences
Mar 31, 2010 |
4.4 / 5 (28) |
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NASA Spots Surprising Shrimp Beneath Antarctic Ice (w/ Video)
(PhysOrg.com) -- At a depth of 600 feet beneath the West Antarctic ice sheet, a small shrimp-like creature managed to brighten up an otherwise gray polar day in November 2009. Bob Bindschadler of NASA's Goddard ...
Space & Earth / Earth Sciences
Mar 15, 2010 |
4.9 / 5 (22) |
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Previously Unknown Volcanic Eruption Helped Trigger Cold Decade
(PhysOrg.com) -- A team of chemists from the U.S. and France has found compelling evidence of a previously undocumented large volcanic eruption that occurred exactly 200 years ago, in 1809.
Space & Earth / Earth Sciences
Oct 29, 2009 |
4.3 / 5 (27) |
9
West Antarctic ice sheet may not be losing ice as fast as once thought
New ground measurements made by the West Antarctic GPS Network (WAGN) project, composed of researchers from The University of Texas at Austin, The Ohio State University, and The University of Memphis, suggest ...
Space & Earth / Earth Sciences
Oct 19, 2009 |
4.2 / 5 (11) |
4
Long debate ended over cause, demise of ice ages -- may also help predict future
Researchers have largely put to rest a long debate on the underlying mechanism that has caused periodic ice ages on Earth for the past 2.5 million years - they are ultimately linked to slight shifts in solar radiation caused ...
Space & Earth / Earth Sciences
Aug 06, 2009 |
4.5 / 5 (24) |
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Ice Sheets Can Retreat 'In a Geologic Instant,' Study of Prehistoric Glacier Shows
(PhysOrg.com) -- Modern glaciers, such as those making up the Greenland and Antarctic ice sheets, are capable of undergoing periods of rapid shrinkage or retreat, according to new findings by paleoclimatologists ...
Space & Earth / Earth Sciences
Jun 21, 2009 |
4.5 / 5 (62) |
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Catastrophic sea levels 'distinct possibility' this century: study
A breakthrough study of fluctuations in sea levels the last time Earth was between ice ages, as it is now, shows that oceans rose some three meters in only decades due to collapsing ice sheets.
Space & Earth / Earth Sciences
Apr 15, 2009 |
4.4 / 5 (90) |
25
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.
