Featured Research

from universities, journals, and other organizations

Spectacular Melting Of The Largest French Glacier

Date:
August 10, 2009
Source:
CNRS (Délégation Paris Michel-Ange)
Summary:
Located over 12 000 kilometers from the Alps, the Kerguelen Islands are home to the largest French glacier, the Cook ice cap (which had an area of around 500 km2 in 1963). By combining historical information with recent satellite data, glaciologists have observed increasingly rapid shrinkage of the ice. Over the last 40 years, the Cook ice cap has thinned by around 1.5 meters per year, its area has decreased by 20%, and retreat has been twice as rapid since 1991.

Spot-5 satellite image: in this 3D view of the Lapparent nunatak (area of rock surrounded by ice), the position of the ice in 1963 and in 2001 has been localized. This has made it possible to estimate glacier thinning (blue arrows).
Credit: Copyright CNES 2003 / Distribution Spot Image / Processing E. Berthier (LEGOS)

Located over 12 000 kilometers from the Alps, the Kerguelen Islands are home to the largest French glacier, the Cook ice cap (which had an area of around 500 km2 in 1963). By combining historical information with recent satellite data, the glaciologists at the Laboratory for Space Studies in Geophysics and Oceanography (Université Paul Sabatier / CNRS / CNES / IRD) have observed increasingly rapid shrinkage of the ice.

Over the last 40 years, the Cook ice cap has thinned by around 1.5 meters per year, its area has decreased by 20%, and retreat has been twice as rapid since 1991. Their work has been just published in the Journal of Geophysical Research.

The Kerguelen Islands are located in the southern Indian Ocean, and numerous glaciers cover the highest areas of the islands. The first studies carried out in this exceptional natural laboratory for French research showed an initially slow retreat of the Ampère glacier (one of the outlet glaciers of the Cook ice cap) between 1800 and 1965, subsequently becoming much faster. Since 1974, in situ monitoring of the Cook ice cap has no longer been carried out. However, observations made from space between 1991 and 2006 have enabled scientists to collect data from this relatively inaccessible area.

Glaciologists from the Laboratory for Space Studies in Geophysics and Oceanography (LEGOS - Université Toulouse 3/CNRS/IRD/CNES) began their work by compiling a complete inventory of the glaciers on the Kerguelen Islands from an Institut Géographique National (IGN) map published in 1967. At that time, these glaciers covered over 700 km2, including 500 km2 for the Cook ice cap alone.

The scientists then used Spot and Landsat satellite images to update this inventory for the years 1991, 2001 and 2003, and to quantify glacial retreat. By 1991, the Cook ice cap covered a mere 448 km2, and by 2003 this had fallen to 403 km2. It has thus lost 20% of its area in 40 years, and it has been retreating twice as fast since 1991. In addition, the researchers estimated the volume loss (or mass balance) of the Cook ice cap over the last 40 years.

This mass balance accurately characterizes the response of the glacier to climatic variation (temperature, precipitation), and can be used to compare glacier response in various areas of the world. For instance, the Cook ice cap has thinned by as much as 300 to 400 meters in glacier tongues at low altitude, whereas variations in thickness appear to be smaller in high regions. On average, for the whole ice cap since 1963, thinning reached 1.5 metres per year, which is a very high value when compared to other glaciers in the world. In the last 40 years, the ice cap has lost about 22% of its volume. This thinning also appears to have been accelerating over the recent period.

The glaciers in the Kerguelen islands were already retreating in the 1960s, and their decline over the past 40 years cannot be attributed only to recent warming partly due to human activities. Part of this retreat can in fact be explained by a delayed response of these glaciers to the natural warming that followed the Little Ice Age (a cold period that ended between 1850 and 1900). However, the recent acceleration of ice wastage is doubtless connected to high temperatures and low precipitation since the beginning of the 1980s.

 


Story Source:

The above story is based on materials provided by CNRS (Délégation Paris Michel-Ange). Note: Materials may be edited for content and length.


Cite This Page:

CNRS (Délégation Paris Michel-Ange). "Spectacular Melting Of The Largest French Glacier." ScienceDaily. ScienceDaily, 10 August 2009. <www.sciencedaily.com/releases/2009/08/090807091435.htm>.
CNRS (Délégation Paris Michel-Ange). (2009, August 10). Spectacular Melting Of The Largest French Glacier. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2009/08/090807091435.htm
CNRS (Délégation Paris Michel-Ange). "Spectacular Melting Of The Largest French Glacier." ScienceDaily. www.sciencedaily.com/releases/2009/08/090807091435.htm (accessed April 17, 2014).

Share This



More Earth & Climate News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) — Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. Video provided by Reuters
Powered by NewsLook.com
Small Reactors Could Be Future of Nuclear Energy

Small Reactors Could Be Future of Nuclear Energy

AP (Apr. 17, 2014) — After the Fukushima nuclear disaster, the industry fell under intense scrutiny. Now, small underground nuclear power plants are being considered as the possible future of the nuclear energy. (April 17) Video provided by AP
Powered by NewsLook.com
Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) — Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com
How Mt. Everest Helped Scientists Research Diabetes

How Mt. Everest Helped Scientists Research Diabetes

Newsy (Apr. 15, 2014) — British researchers were able to use Mount Everest's low altitudes to study insulin resistance. They hope to find ways to treat diabetes. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins