Featured Research

from universities, journals, and other organizations

Debris on certain Himalayan glaciers may prevent melting

Date:
January 25, 2011
Source:
University of California - Santa Barbara
Summary:
A new scientific study shows that debris coverage -- pebbles, rocks and debris from surrounding mountains -- may be a missing link in the understanding of the decline of glaciers. Debris is distinct from soot and dust, according to the scientists.

These are crevasses of a steep glacier in the Sutlej Valley of the Western Himalaya. This glacier has a debris-covered toe.
Credit: Bodo Bookhagen, UCSB

A new scientific study shows that debris coverage -- pebbles, rocks, and debris from surrounding mountains -- may be a missing link in the understanding of the decline of glaciers. Debris is distinct from soot and dust, according to the scientists.

Melting of glaciers in the Himalayan Mountains affects water supplies for hundreds of millions of people living in South and Central Asia. Experts have stated that global warming is a key element in the melting of glaciers worldwide.

Bodo Bookhagen, assistant professor in the Department of Geography at UC Santa Barbara, co-authored a paper on this topic in Nature Geoscience. The first author is Dirk Scherler, Bookhagen's graduate student from Germany, who performed part of this research while studying at UCSB.

"With the aid of new remote-sensing methods and satellite images, we identified debris coverage to be an important contributor to glacial advance and retreat behaviors," said Bookhagen. "This parameter has been almost completely neglected in previous Himalayan and other mountainous region studies, although its impact has been known for some time."

The finding is one more element in a worldwide political controversy involving global warming. "Controversy about the current state and future evolution of Himalayan glaciers has been stirred up by erroneous reports by the Intergovernmental Panel on Climate Change (IPCC)," according to the paper.

"There is no 'stereotypical' Himalayan glacier," said Bookhagen. "This is in clear contrast to the IPCC reports that lumps all Himalayan glaciers together."

Bookhagen noted that glaciers in the Karakoram region of Northwestern Himalaya are mostly stagnating. However, glaciers in the Western, Central, and Eastern Himalaya are retreating, with the highest retreat rates -- approximately 8 meters per year -- in the Western Himalayan Mountains. The authors found that half of the studied glaciers in the Karakoram region are stable or advancing, whereas about two-thirds are in retreat elsewhere throughout High Asia. This is in contrast to the prevailing notion that all glaciers in the tropics are retreating.

Bookhagen explained the difference between debris and coverage by soot and dust on glaciers: "The debris cover has the opposite effect of soot and dust on glaciers. Debris coverage thickness above 2 centimeters, or about a half an inch, 'shields' the glacier and prevents melting. This is the case for many Himalayan glaciers that are surrounded by towering mountains that almost continuously shed pebbles, debris, and rocks onto the glacier."

Thus, glaciers in the steep Himalaya are not only affected by temperature and precipitation, but also by debris coverage, and have no uniform and less predictable response, explained the authors. The debris coverage may be one of the missing links to creating a more coherent picture of glacial behavior throughout all mountains. The scientists contrast this Himalayan glacial study with glaciers from the gently dipping, low-relief Tibetan Plateau that have no debris coverage. Those glaciers behave in a different way, and their frontal changes can be explained by temperature and precipitation changes.

Bookhagen described results of another of his recent studies on this topic. He said that one of the key findings was that the Western Himalaya, including the Indus catchment and regions in Northern Pakistan and Northwestern India, depend heavily on seasonal snow and glacial melt waters, while Central Himalayan regions -- Western India and Nepal -- mostly depend on monsoonal rainfall.

The smaller seasonal water storage space in the Central Himalaya, which has only steep glaciers and no large snow fields, makes this region much more vulnerable to shifts in monsoonal strength and to glacial melting, explained Bookhagen. River discharge in these regions is crucial to sustain agriculture, hydropower, and drinking water. If the Indian monsoon season is weaker because of global atmospheric changes such as El Niño, then Central Nepal must primarily rely on water coming from the seasonal melting of glaciers and the small amount of snowmelt that is available.

"Retreating glaciers, and thus a reduction of seasonal water storage in this region, have a large impact on hundreds of millions of people living in the downstream section of these rivers," said Bookhagen. "The mitigation and adaptation strategies in the Himalaya Mountains thus need to take into account the spatial climatic and topographic variability. There is no regional solution, but only different local strategies to the future water shortage. The geographic setting of High Asia poses political difficulties as future water treaties need to be carefully evaluated."


Story Source:

The above story is based on materials provided by University of California - Santa Barbara. Note: Materials may be edited for content and length.


Journal Reference:

  1. Dirk Scherler, Bodo Bookhagen, Manfred R. Strecker. Spatially variable response of Himalayan glaciers to climate change affected by debris cover. Nature Geoscience, 2011; DOI: 10.1038/ngeo1068

Cite This Page:

University of California - Santa Barbara. "Debris on certain Himalayan glaciers may prevent melting." ScienceDaily. ScienceDaily, 25 January 2011. <www.sciencedaily.com/releases/2011/01/110124162708.htm>.
University of California - Santa Barbara. (2011, January 25). Debris on certain Himalayan glaciers may prevent melting. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2011/01/110124162708.htm
University of California - Santa Barbara. "Debris on certain Himalayan glaciers may prevent melting." ScienceDaily. www.sciencedaily.com/releases/2011/01/110124162708.htm (accessed August 1, 2014).

Share This




More Earth & Climate News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) — Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Florida Panther Rebound Upsets Ranchers

Florida Panther Rebound Upsets Ranchers

AP (July 31, 2014) — With Florida's panther population rebounding, some ranchers complain the protected predators are once again killing their calves. (July 31) Video provided by AP
Powered by NewsLook.com
Big Waves In Arctic Ocean Threaten Polar Ice

Big Waves In Arctic Ocean Threaten Polar Ice

Newsy (July 30, 2014) — Big waves in parts of the Arctic Ocean are unprecedented, mainly because they used to be covered in ice. Video provided by Newsy
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) — Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
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