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 January 29, 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 January 29, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Thursday, January 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Scientists Say Earliest Snakes Lived Alongside The Dinosaurs

Scientists Say Earliest Snakes Lived Alongside The Dinosaurs

Newsy (Jan. 28, 2015) Wrongly categorized as lizard fossils, snake fossils now show the reptile could have developed earlier than we thought — 70 million years earlier. Video provided by Newsy
Powered by NewsLook.com
Mobile Heat Tech the Google Maps of Energy Savings

Mobile Heat Tech the Google Maps of Energy Savings

Reuters - Innovations Video Online (Jan. 28, 2015) A Boston company has come up with a new and efficient way for homeowners to save money on energy costs, a timely innovation given the impact of this week&apos;s snow storms in the northeast US. The company is using a newly developed technology that can map heat signatures for entire cities in matter of days, generating data that could potentially produce billions in energy savings. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Time Lapse: Sculptures Created from 30 Tons of Snow

Time Lapse: Sculptures Created from 30 Tons of Snow

Rumble (Jan. 28, 2015) Students in North Finland use 30 tons of snow and one ton of ice to build a massive photography display and sculpture installation. Five days of work condensed into a one-minute time lapse! Video provided by Rumble
Powered by NewsLook.com
Scientists Hold Emergency Meeting to Save Endangered Rhinos

Scientists Hold Emergency Meeting to Save Endangered Rhinos

AFP (Jan. 28, 2015) Conservationists and scientists hold talks in Kenya to come up with a last ditch plan to save the northern white rhinoceros from extinction. Duration: 01:06 Video provided by AFP
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