Ice age
hideThe general term "ice age" or, more precisely, "glacial age" denotes a geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in an expansion of continental ice sheets, polar ice sheets and alpine glaciers. Within a long-term ice age, individual pulses of extra cold climate are termed "glaciations". Glaciologically, ice age implies the presence of extensive ice sheets in the northern and southern hemispheres; by this definition we are still in an ice age (because the Greenland and Antarctic ice sheets still exist).
More colloquially, when speaking of the last few thousand years, "the" ice age refers to the most recent colder period (or freezing period) with extensive ice sheets over the North American and Eurasian continents: in this sense, the most recent ice age peaked, in its Last Glacial Maximum about 20,000 years ago. This article will use the term ice age in the former, glaciological, sense: glacials for colder periods during ice ages and interglacials for the warmer periods.
For more information about Ice age, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with ice age
Past regional cold and warm periods linked to natural climate drivers
Space & Earth / Earth Sciences
Nov 26, 2009 |
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Intervals of regional warmth and cold in the past are linked to the El Niño phenomenon and the so-called "North Atlantic Oscillation" in the Northern hemisphere's jet stream, according to a team of climate scientists. These ...
Supervolcano eruption -- in Sumatra -- deforested India 73,000 years ago
Space & Earth / Earth Sciences
Nov 23, 2009 |
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A new study provides "incontrovertible evidence" that the volcanic super-eruption of Toba on the island of Sumatra about 73,000 years ago deforested much of central India, some 3,000 miles from the epicenter, ...
After mastodons and mammoths, a transformed landscape
Space & Earth / Earth Sciences
Nov 19, 2009 |
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(PhysOrg.com) -- Roughly 15,000 years ago, at the end of the last ice age, North America's vast assemblage of large animals -- including such iconic creatures as mammoths, mastodons, camels, horses, ground ...
Life's Ancient Island in the Ice
Space & Earth / Earth Sciences
Oct 29, 2009 |
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During the last ice age, massive glaciers covered much of our planet. However, a region of Alaska, Siberia and the Canadian Yukon remained ice-free. This region, known as Beringia, supported unique organisms ...
Volcanoes played pivotal role in ancient ice age, mass extinction
Space & Earth / Earth Sciences
Oct 26, 2009 |
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(PhysOrg.com) -- Researchers here have discovered the pivotal role that volcanoes played in a deadly ice age 450 million years ago.
Arctic land and seas account for up to 25 percent of world's carbon sink
Space & Earth / Earth Sciences
Oct 14, 2009 |
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In a new study in the journal Ecological Monographs, ecologists estimate that Arctic lands and oceans are responsible for up to 25 percent of the global net sink of atmospheric carbon dioxide. Under curren ...
Small mammals have a 'Celtic fringe' too
Sep 30, 2009 |
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The origin of the 'Celtic fringe' of genetically and culturally distinctive people in the northern and western British Isles is the source of fierce academic controversy.
Scandinavians are descended from Stone Age immigrants
Sep 24, 2009 |
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(PhysOrg.com) -- Today's Scandinavians are not descended from the people who came to Scandinavia at the conclusion of the last ice age but, apparently, from a population that arrived later, concurrently with the introduction ...
Peruvian glacial retreats linked to European events of Little Ice Age
Space & Earth / Earth Sciences
Sep 24, 2009 |
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(PhysOrg.com) -- A new study that reports precise ages for glacial moraines in southern Peru links climate swings in the tropics to those of Europe and North America during the Little Ice Age approximately ...
Europe's first farmers replaced their Stone Age hunter-gatherer forerunners
Other Sciences / Archaeology & Fossils
Sep 03, 2009 |
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(PhysOrg.com) -- DNA study suggests that further waves of prehistoric immigration are waiting to be discovered. Central and northern Europe's first farmers were immigrants with barely any ancestral ties to the modern population, ...
Long debate ended over cause, demise of ice ages -- may also help predict future
Space & Earth / Earth Sciences
Aug 06, 2009 |
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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 ...
3.2-Million-Year Temperature History from Tiny Fossils
Space & Earth / Earth Sciences
Aug 05, 2009 |
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(PhysOrg.com) -- People often talk about greenhouse gases and their effect on the earth's climate as if those effects were new. But greenhouse gases have been around for hundreds of millennia, playing a key ...
Massive glacier in sub-Antarctic island shrinks by a fifth
Space & Earth / Earth Sciences
Jul 22, 2009 |
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One of the biggest glaciers in the southern hemisphere shrivelled by a fifth in 40 years, French scientists said on Wednesday.
Research indicates ocean current shutdown may be gradual
Space & Earth / Earth Sciences
Jul 16, 2009 |
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The findings of a major new study are consistent with gradual changes of current systems in the North Atlantic Ocean, rather than a more sudden shutdown that could lead to rapid climate changes in Europe and elsewhere.
Steppe change: Mammoths roamed southern Spain
Other Sciences / Archaeology & Fossils
Jul 09, 2009 |
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Remains of woolly mammoths have been found in southern Spain, proving that the chilly grip of the last Ice Age extended farther south than thought, palaeontologists said on Thursday.
