Related topics: climate change · glaciers · sea level rise · sea level · ice

Clouds with a chance of warming

Researchers from Argonne's Environmental Science division participated in one of the largest collaborative atmospheric measurement campaigns in Antarctica in recent decades.

Greenland ice sheet faces irreversible melting

In a study published this week in The Cryosphere, researchers from the National Centre for Atmospheric Science and University of Reading demonstrate how climate change could lead to irreversible sea level rise as temperatures ...

Melting of polar ice shifting Earth itself, not just sea levels

The melting of polar ice is not only shifting the levels of our oceans, it is changing the planet Earth itself. Newly minted Ph.D. Sophie Coulson and her colleagues explained in a recent paper in Geophysical Research Letters ...

'Frozen in time' landscape discovered under Antarctic ice

Scientists revealed Tuesday that they had discovered a vast, hidden landscape of hills and valleys carved by ancient rivers that has been "frozen in time" under the Antarctic ice for millions of years.

Earth risks tipping into 'hothouse' state: study

The planet urgently needs to transition to a green economy because fossil fuel pollution risks pushing the Earth into a lasting and dangerous "hothouse" state, researchers warned on Monday.

Warming Greenland ice sheet passes point of no return

Nearly 40 years of satellite data from Greenland shows that glaciers on the island have shrunk so much that even if global warming were to stop today, the ice sheet would continue shrinking.

page 1 from 40

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.

This text uses material from Wikipedia, licensed under CC BY-SA