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

Catastrophic outburst floods carved Greenland's 'Grand Canyon'

Buried a mile beneath Greenland's thick ice sheet is a network of canyons so deep and long that the largest of these has been called Greenland's "Grand Canyon." This megacanyon's shape suggests it was carved by running water ...

Fossil frogs offer insights into ancient Antarctica

The discovery of the earliest known modern amphibians in Antarctica provides further evidence of a warm and temperate climate in the Antarctic Peninsula before its separation from the southern supercontinent, Gondwana. The ...

2019 was Europe's hottest year ever: EU

Last year was the hottest in history across Europe as temperature records were shattered by a series of extreme heatwaves, the European Union's satellite monitoring surface said Wednesday.

Eurasian ice sheet collapse raised seas eight metres: study

The melting of the Eurasian ice sheet around 14,000 years ago lifted global sea levels by about eight metres, according to new research published Monday that highlights the risks of today's rapid ice cap melt.

Unusually clear skies drove record loss of Greenland ice in 2019

Last year was one of the worst years on record for the Greenland ice sheet, which shrunk by hundreds of billions of tons. According to a study published today in The Cryosphere, that mind-boggling ice loss wasn't caused by ...

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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.

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