Tag Archives: ice cap

Thawing ‘Dry Ice’ Drives Groovy Action on Mars

PASADENA, Calif. — Researchers using NASA’s Mars Reconnaissance Orbiter see seasonal changes on far-northern Martian sand dunes caused by warming of a winter blanket of frozen carbon dioxide.

Earth has no naturally frozen carbon dioxide, though pieces of manufactured carbon-dioxide ice, called “dry ice,” sublime directly from solid to gas on Earth, just as the vast blankets of dry ice do on Mars. A driving factor in the springtime changes where seasonal coverings of dry ice form on Mars is that thawing occurs at the underside of the ice sheet, where it is in contact with dark ground being warmed by early-spring sunshine through translucent ice. The trapped gas builds up pressure and breaks out in various ways. (more…)

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Ancient Story of Dartmoor Tors Has an Ice-Cold Twist

Ice extended further across the UK than previously thought and played a part in sculpting the rocky landscape of Dartmoor in South West England during the last Ice Age, according to new research which challenges previously held theories.

A study of the National Park area of Dartmoor, UK, shows for the first time that an ice cap and valley glaciers were present in its centre and that the naturally castellated stone outcrops, known as tors, were survivors.

The new research by the Universities of Durham and Exeter, and Stockton Riverside College, is published in the journal Quaternary Science Reviews.

Researchers, who carried out detailed observations on the ground and using aerial photography, say the evidence includes glacial features such as elongated rounded mounds or drumlins and hummocky landforms or moraines. Similar features may also exist in other upland areas of southwest England, indicating that small upland glaciers were regularly hosted in the region during periods of glaciation. (more…)

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New CU-led Study May Answer Long-Standing Questions About Enigmatic Little Ice Age

A new University of Colorado Boulder-led study appears to answer contentious questions about the onset and cause of Earth’s Little Ice Age, a period of cooling temperatures that began after the Middle Ages and lasted into the late 19th century.

According to the new study, the Little Ice Age began abruptly between A.D. 1275 and 1300, triggered by repeated, explosive volcanism and sustained by a self- perpetuating sea ice-ocean feedback system in the North Atlantic Ocean, according to CU-Boulder Professor Gifford Miller, who led the study. The primary evidence comes from radiocarbon dates from dead vegetation emerging from rapidly melting icecaps on Baffin Island in the Canadian Arctic, combined with ice and sediment core data from the poles and Iceland and from sea ice climate model simulations, said Miller. (more…)

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