Quelccaya Ice Cap

Infobox_Glacier | glacier_name = Quelccaya Ice Cap

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caption = 1975-2000 Landsat false-colour animation, Qori Kalis outflow glacier at left centre
type = Mountain glacier/Icecap
location = Peru
coordinates = coord|13|56|0|S|70|50|0|W|type:glacier
area = 44 km² (17 mi²)
length =
thickness =
terminus = Outlet glaciers
status = RetreatingThe Quelccaya Ice Cap is the largest glaciated area in the tropics. Located in the Cordillera Oriental section of the Andes mountains of Peru, the ice cap is at an average altitude of 5,470 meters (18,600 ft) and spans an area of 44 square kilometers (17 mi²). As with the majority of the Earth's glaciers, the Quelccaya Ice cap has retreated significantly since it was first studied. Since 1978 the icecap has lost approximately 20% of its area, [*cite web | last = | first = | authorlink = | coauthors = | year = | url = http://sciencebulletins.amnh.org/earth/f/glaciers.20050331/essays/52_1.php | title = The Ice Plant Cometh | format = | work = Science Bulletins | publisher = American Museum of Natural History | accessdate = 2006-08-09 | accessyear =] and the rate of retreat is presently increasing. Comparing pictures taken in 1963 and 1978, an annual retreat rate of 4.7 meters (15.4 ft) was estimated. In the first few years of the 21st century, the annual retreat was measured to be as much as 205 meters (672 ft), more than 40 times as fast. [cite web | last = | first = | authorlink = | coauthors = | date = November 6, 2003 | url = http://earthobservatory.nasa.gov/Newsroom/MediaAlerts/2003/2003110616154.html | title = Ice-Cores May Yield Clues to 5,000-Year-Old Mystery | format = | work = | publisher = NASA Earth Observatory | accessdate = 2006-08-09 | accessyear =] The major outlet glacier from the Quelccaya Ice Cap, the Qori Kalis Glacier, has also retreated significantly since 1963.

Ice core study

Lonnie Thompson and his research team have drilled ice cores from Quelccaya that date back almost 2,000 years and have used them to study changes in atmospheric conditions over this period. In these samples, the oxygen isotope ratio, oxygen-18 to oxygen-16, has risen abruptly in the last 50 years, an indicator of regional warming. As the ice cap is retreating, it is exposing almost perfectly preserved, unfossilized plant specimens that have been dated to 5,200 years before present, indicating that it has been more than 50 centuries since the ice cap was smaller than it is today. [cite web | last = | first = | authorlink = | coauthors = | date = June 25, 2006 | url = http://www.terradaily.com/reports/Tropical_Ice_Cores_Shows_Two_Abrupt_Global_Climate_Shifts_999.html | title = Tropical Ice Cores Shows Two Abrupt Global Climate Shifts | format = | work = | publisher = Terradaily | accessdate = 2006-08-09 | accessyear =]

Ice cores taken from Upper Fremont Glacier in the U.S. state of Wyoming show an oxygen isotope profile similar to that of the Quelccaya ice cores at the end of the Little Ice Age, a period of cooler global temperatures between the years 1550 and 1850. The sudden alterations in the oxygen isotope ratio found in ice core samples from these two glaciers, which are at great distance from each other, provide evidence of a sudden global climate change in the mid-latitude regions of the planet at this time. [cite web | last = Reddy | first = M.M. | authorlink = | coauthors = D.L. Naftz, P.F. Schuster | year = | url = http://wwwbrr.cr.usgs.gov/projects/SW_corrosion/icecore/ | title = Ice-Core Evidence of Rapid Climate Shift during the Termination of the Little Ice Age | format = | work = | publisher = U.S. Geological Survey | accessdate = 2006-08-09 | accessyear =]

ee also

*List of glaciers
*Water supply and sanitation in Peru

Cited references