Featured Research

from universities, journals, and other organizations

Measuring The Retreat History Of Alpine Glaciers

Date:
July 25, 2007
Source:
Geological Society of America
Summary:
The lengths of alpine glaciers quickly adjust to changes in temperature and precipitation, making them sensitive indicators of climate. Recording changes in length of current glaciers is a matter of visual observation. However, for glaciers that existed in the past, documenting the changes in length often requires rare geological and glaciological circumstances.

The lengths of alpine glaciers quickly adjust to changes in temperature and precipitation, making them sensitive indicators of climate.

Related Articles


Recording changes in length of current glaciers is a matter of visual observation. However, for glaciers that existed in the past, documenting the changes in length often requires rare geological and glaciological circumstances.

The Animas River drainage of Colorado's San Juan Mountains allows documentation of the demise of a large alpine valley glacier from its Last Glacial Maximum extent. Approximately 20,000 years before present (B.P.), the Animas Valley glacier lobe of the San Juan Ice cap extended 91 kilometers from the ice divide, and pervasively polished crystalline bedrock.

To document the retreat history of this glacier, Guido et al. measured the concentration of cosmogenically produced 10Be in polished bedrock to deduce the duration of exposure to cosmic rays since the glacier receded past each of eight locations. This yielded a record of retreat that began at approximately 19,500 years B.P and ended at roughly 12,500 years B.P., when the San Juan Mountains became largely devoid of ice.

This history implies that the demise of the Animas Valley glacier was protracted, coincided with a gradual rise in solar radiation, and was perhaps fastest during a time of regional drying recorded in shoreline elevations of lakes in western North America.

Reference: "Pacing the post--Last Glacial Maximum demise of the Animas Valley glacier and the San Juan Mountain ice cap," Zackry S. Guido et al., University of Colorado, Geology, Pages 739-742.


Story Source:

The above story is based on materials provided by Geological Society of America. Note: Materials may be edited for content and length.


Cite This Page:

Geological Society of America. "Measuring The Retreat History Of Alpine Glaciers." ScienceDaily. ScienceDaily, 25 July 2007. <www.sciencedaily.com/releases/2007/07/070723160137.htm>.
Geological Society of America. (2007, July 25). Measuring The Retreat History Of Alpine Glaciers. ScienceDaily. Retrieved March 4, 2015 from www.sciencedaily.com/releases/2007/07/070723160137.htm
Geological Society of America. "Measuring The Retreat History Of Alpine Glaciers." ScienceDaily. www.sciencedaily.com/releases/2007/07/070723160137.htm (accessed March 4, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Wednesday, March 4, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Tourists Visit Rare Grey Whales in Mexico

Raw: Tourists Visit Rare Grey Whales in Mexico

AP (Mar. 4, 2015) Once nearly extinct, grey whales now migrate in their thousands to Mexico&apos;s Vizcaino reserve in Baja California, in search of warmer waters to mate and give birth. Tourists flock to the reserve to see the whales, measuring up to 49 feet long. (March 4) Video provided by AP
Powered by NewsLook.com
Raw: Injured Miners Treated After Blast

Raw: Injured Miners Treated After Blast

AP (Mar. 4, 2015) An explosion ripped through a coal mine before dawn Wednesday in war-torn eastern Ukraine, killing at least one miner, officials said. Graphic video of injured miners being treated in a Donetsk hospital. (March 4) Video provided by AP
Powered by NewsLook.com
Australian Museum Shares Terrifying Goblin Shark With the World

Australian Museum Shares Terrifying Goblin Shark With the World

Buzz60 (Mar. 4, 2015) The Australian Museum has taken in its fourth-ever goblin shark, a rare fish with an electricity-sensing snout and &apos;alien-like&apos; jaw. Mike Janela (@mikejanela) takes a look. Video provided by Buzz60
Powered by NewsLook.com
Mount Everest Has a Poop Problem

Mount Everest Has a Poop Problem

Buzz60 (Mar. 4, 2015) With no bathrooms to use, climbers of Mount Everest have been leaving human waste on the mountain for years, and it&apos;s becoming a health issue. Mike Janela (@mikejanela) has more. Video provided by Buzz60
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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