ESA : Upsala Glacier .- El Glaciar Upsala en la Patagonia, Argentina....

http://www.esa.int/spaceinimages/Images/2016/08/Upsala_Glacier

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Details

• Title Upsala Glacier
• Released 02/09/2016 10:00 am
• Copyright Contains modified Copernicus Sentinel data (2016), processed by ESA
• Description
  The Upsala Glacier in Argentina’s Los Glaciares National Park is pictured in this Sentinel-2A image from 22 January 2016.
  The park was named a UNESCO World Heritage site in 1981 and is the largest in the country, covering an area of over 7000 sq km.
  Many glaciers in the national park and in the wider Patagonian Ice Field have been retreating during the last 50 years because of rising temperatures. Upsala Glacier has retreated more than 3 km in the past 15 years.
  Glaciers are the largest reservoirs of freshwater on our planet, and their melting or growing is one of the best indicators of climate change. Satellite data can help to monitor changes in glacier mass and, subsequently, their contribution to rising sea levels. 
  Taking a closer look at the terminus of the Upsala Glacier, we can see how icebergs have broken off and are floating in the water of the upper reaches of Lake Argentino. The lake’s unique colour is attributed to ‘glacier milk’ – suspended fine sediment produced by the abrasion of glaciers rubbing against rock.
  The darker lines following the flow of the glacier are moraines: accumulations of rock, soil and other debris – including glacial milk – that have been deposited by the glacier.
  This image is also featured on the Earth from Space video programme.
• Id 364438

TAGS

• Click on the tags to find the matching images.
• Activity Observing the Earth
• Mission Sentinel-2
• System Copernicus
• Location Argentina , Patagonia
• Keywords Ice , Glaciers
• Set Earth observation image of the week

ESA
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com
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NASA : Upsala Glacier Retreat

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Upsala Glacier Retreat

This photograph by an astronaut on the International Space Station highlights the snout of the Upsala Glacier (49.88°S, 73.3°W) on the Argentine side of the North Patagonian Icefield. Ice flow in this glacier comes from the north (right in this rotated image). Dark lines of rocky debris (moraine) within the ice give a sense of the slow ice flow from right to left.

A smaller, side glacier joins Upsala at the present-day ice front -- the wall from which masses of ice periodically collapse into Lago (Lake) Argentino. In this image, the 2.7 kilometer-wide ice front casts a thin, dark shadow. The surface of Lago Argentino is whitened by a mass of debris from a recent collapse of the ice wall. Larger icebergs appear as white dots on the lake surface at image left.

Remotely sensed data, including astronaut images, have recorded the position of the ice front over the years. A comparison of this October 2013 image with older data (January 2004 and January 2001, as well as October 2009) indicates that the ice front has moved backwards -- upstream -- about 3 kilometers (2 miles). This retreat is believed by scientists to indicate climate warming in this part of South America. The warming not only causes the ice mass to retreat, but also to thin. A study of 63 glaciers by Rignot et al has shown that this is a general trend in Patagonia.

The water color in Lago Argentino is related to the glacier flow. The lake receives most of the ice from the glacier and thus receives most of the “rock flour” -- rocks ground to white powder by the ice scraping against the rock floor of the valley. Glacial flour turns the lake a gray-green hue in this image. The darker blue of the smaller lakes (image bottom) indicates that they are receiving much less rock flour.

This image was taken on Oct. 2, 2013, with a Nikon D3 digital camera using a 300 millimeter lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. It has been cropped and enhanced to improve contrast, and lens artifacts have been removed.

> View the annotated version of this image at NASA's Earth Observatory website

Image Credit: NASA
Caption: M. Justin Wilkinson, Jacobs at NASA-Johnson Space Center

NASA

Guillermo Gonzalo Sánchez Achutegui

ayabaca@gmail.com

ayabaca@hotmail.com

ayabaca@yahoo.com

Inscríbete en el Foro del blog y participa : A Vuelo De Un Quinde - El Foro!