News tagged with ice sheet
Greenland's current loss of ice mass
The Greenland ice sheet continues to lose mass and thus contributes at about 0.7 millimeters per year to the currently observed sea level change of about 3 mm per year. This trend increases each year by a further 0.07 millimeters ...
Space & Earth / Earth Sciences
May 29, 2012 |
5 / 5 (5) |
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Finding fingerprints in sea level rise
It was used to help Apollo astronauts navigate in space, and has since been applied to problems as diverse as economics and weather forecasting, but Harvard scientists are now using a powerful statistical tool to not only ...
Space & Earth / Earth Sciences
May 18, 2012 |
4 / 5 (12) |
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Seeking signs of life at the glacier's edge
Microbes living at the edges of Arctic ice sheets could help researchers pinpoint evidence for similar microorganisms that could have evolved on Mars, the Jovian moon Europa, or Saturn's moon Enceladus.
Space & Earth / Earth Sciences
May 17, 2012 |
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Climate scientists discover new weak point of the Antarctic ice sheet
The Filchner-Ronne Ice Shelf fringing the Weddell Sea, Antarctica, may start to melt rapidly in this century and no longer act as a barrier for ice streams draining the Antarctic Ice Sheet. These predictions ...
Space & Earth / Earth Sciences
May 09, 2012 |
4.1 / 5 (20) |
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Antarctic octopus tells story of ice-sheet collapse
Scientists have long been concerned that the massive West Antarctic Ice Sheet could collapse if global temperatures keep climbing. If it did, sea levels are predicted to rise by as much as five meters.
Space & Earth / Earth Sciences
May 07, 2012 |
4.3 / 5 (13) |
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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 |
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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) |
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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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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 |
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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) |
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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 |
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Study finds warm ocean currents cause majority of ice loss from Antarctica
Reporting this week in the journal Nature, an international team of scientists led by British Antarctic Survey (BAS) has established that warm ocean currents are the dominant cause of recent ice loss from A ...
Space & Earth / Earth Sciences
Apr 25, 2012 |
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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 |
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Global sea level likely to rise as much as 70 feet for future generations
Even if humankind manages to limit global warming to 2 degrees C (3.6 degrees F), as the Intergovernmental Panel on Climate Change recommends, future generations will have to deal with sea levels 12 to 22 meters (40 to 70 ...
Space & Earth / Earth Sciences
Mar 19, 2012 |
3.3 / 5 (32) |
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Geophysicists employ novel method to identify sources of global sea level rise
As the Earth's climate warms, a melting ice sheet produces a distinct and highly non-uniform pattern of sea-level change, with sea level falling close to the melting ice sheet and rising progressively farther away. The pattern ...
Space & Earth / Earth Sciences
Apr 24, 2012 |
4.1 / 5 (8) |
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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.
