A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. , on the other hand, are periods of warmer climate between glacial periods. The Last Glacial Period ended about 15,000 years ago.
Quaternary Period
Within the
Quaternary, which started about 2.6 million years
before present, there have been a number of glacials and interglacials.
At least eight glacial cycles have occurred in the last 740,000 years alone.
Changes in atmospheric and associated radiative forcing were among the primary drivers of globally cold glacial and warm interglacial climates
, with changes in ocean physical circulation, biological productivity and seawater acid-base chemistry likely causing most of the recorded changes
Penultimate Glacial Period
The Penultimate Glacial Period (PGP) is the glacial period that occurred before the Last Glacial Period. It began about 194,000 years ago and ended 135,000 years ago, with the beginning of the
Eemian interglacial.
Last Glacial Period
The last glacial period was the most recent glacial period within the Quaternary glaciation at the end of the
Pleistocene, and began about 110,000 years ago and ended about 11,700 years ago.
The glaciations that occurred during the glacial period covered many areas of the Northern Hemisphere and have different names, depending on their geographic distributions:
Wisconsin (in
North America),
Devensian (in
Great Britain),
Midlandian (in
Ireland),
Würm (in the
Alps),
Weichsel (in northern
Central Europe),
Dali (in
East China),
Beiye (in
North China),
Taibai (in
Shaanxi)
Luoji Shan (in southwest
Sichuan),
Zagunao (in northwest
Sichuan),
Tianchi (in the
Tian Shan)
Jomolungma (in the
Himalayas), and
Llanquihue (in
Chile). The glacial advance reached the Last Glacial Maximum about 26,500
Before Present. In
Europe, the ice sheet reached
Northern Germany. Over the last 650,000 years, there have been on average seven cycles of glacial advance and retreat.
Next glacial period
Since orbital variations are predictable,
computer models that relate orbital variations to climate can predict future climate possibilities.
Work by Berger and Loutre suggests that the current warm climate may last another 50,000 years.
The amount of heat trapping (greenhouse) gases being emitted into the Earth's oceans and its atmosphere may delay the next glacial period by an additional 50,000 years.
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