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Southern Patagonia Icefield (NASA, International Space Station, 02/14/14)

This grand panorama of the Southern Patagonia Icefield (center) was imaged by an Expedition 38 crew member on the International Space Station on one of the rare clear days in the southern Andes Mountains. With an area of 13,000 square kilometers, the icefield is the largest temperate ice sheet in the Southern Hemisphere.

 

Storms that swirl into the region from the southern Pacific Ocean (top) bring rain and snow (equivalent to a total of 2-11 meters of rainfall per year) resulting in the buildup of the ice sheet shown here (center). During the ice ages the glaciers were far larger. Geologists now know that ice tongues extended far onto the plains in the foreground, completely filling the great Patagonian lakes on repeated occasions.

 

Similarly, ice tongues extended into the dense network of fjords (arms of the sea) on the Pacific side of the icefield. Ice tongues today appear tiny compared to the view that an "ice age" astronaut would have seen. A study of the surface topography of sixty-three glaciers, based on Shuttle Radar Topography Mission (SRTM) data, compared data from 2000 to data from studies going back about 30 years (1968-1975). Many glacier tongues showed significant annual "retreat" of their ice fronts, a familiar signal of climate change. The study also revealed that the almost invisible loss by glacier thinning is far more significant in explaining ice loss.

 

The researchers concluded that volume loss by frontal collapse is 4-10 times smaller than that caused by thinning. Scaled over the entire icefield, including frontal loss (so-called calving when ice masses collapse into the lakes), it was calculated that 13.5 cubic kilometers of ice was lost each year over the study period. This number becomes more meaningful compared with the rate measured in the last five years of the study (1995-2000), when the rate increased almost threefold, averaging 38.7 cubic kilometers per year.

 

Extrapolating results from the low altitude glacier tongues implies that the high plateau ice on the spine of the Andes is thinning as well. In the decade since this study the often-imaged Upsala Glacier has retreated a further three kilometers, as shown recently in images taken by crew members aboard the space station. Glacier Pio X, named for Pope Pius X, is the only large glacier that is growing in length.

 

About Crew Earth Observations:

 

In Crew Earth Observations (CEO), crewmembers on the International Space Station (ISS) photograph the Earth from their unique point of view located 200 miles above the surface. Photographs record how the planet is changing over time, from human-caused changes like urban growth and reservoir construction, to natural dynamic events such as hurricanes, floods and volcanic eruptions. A major emphasis of CEO is to monitor disaster response events in support of the International Disaster Charter (IDC). CEO imagery provides researchers on Earth with key data to understand the planet from the perspective of the ISS. Crewmembers have been photographing Earth from space since the early Mercury missions beginning in 1961. The continuous images taken from the ISS ensure this record remains unbroken.

 

Image credit: NASA

 

Original image:

www.nasa.gov/content/southern-patagonia-icefield/

 

More about space station research:

www.nasa.gov/mission_pages/station/research/index.html

 

View more photos like this in the "NASA Earth Images" Flickr photoset:

www.flickr.com/photos/28634332@N05

 

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These official NASA photographs are being made available for publication by news organizations and/or for personal use printing by the subject(s) of the photographs. The photographs may not be used in materials, advertisements, products, or promotions that in any way suggest approval or endorsement by NASA. All Images used must be credited. For information on usage rights please visit: www.nasa.gov/audience/formedia/features/MP_Photo_Guidelin...

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Uploaded on March 3, 2014
Taken on February 13, 2014