Featured Research

from universities, journals, and other organizations

Fast-shrinking Greenland glacier experienced rapid growth during cooler times

Date:
July 15, 2011
Source:
University at Buffalo
Summary:
Large, marine-calving glaciers have the ability not only to shrink rapidly in response to global warming, but to grow at a remarkable pace during periods of global cooling, according to geologists working in Greenland.

Jakobshavn Isbrae, a Greenland glacier, has retreated rapidly between 1850 and 2010. A new UB study shows that its rate of advance during cooler times was just as fast.
Credit: Bea Csatho

Large, marine-calving glaciers have the ability not only to shrink rapidly in response to global warming, but to grow at a remarkable pace during periods of global cooling, according to University at Buffalo geologists working in Greenland.

The conclusion stems from new research on Jakobshavn Isbrae, a tongue of ice extending out to sea from Greenland's west coast. Through an analysis of adjacent lake sediments and plant fossils, the UB team determined that the glacier, which retreated about 40 kilometers inland between 1850 and 2010, expanded outward at a similar pace about 200 years ago, during a time of cooler temperatures known as the Little Ice Age.

A paper detailing the results is available online in Quaternary Science Reviews.

"We know that Jakobshavn Isbrae has retreated at this incredible rate in recent years, and our study suggests that it advanced that fast, also," said Jason Briner, the associate professor of geology who led the research. His team included master's and PhD students from UB and Brown University.

"Our results support growing evidence that calving glaciers are particularly sensitive to climate change," Briner added.

Jakobshavn Isbrae has been the focus of intense scientific interest because it is one of the world's fastest-flowing glacier, releasing enormous quantities of Greenland's ice into the ocean. Changes in the rate at which icebergs calve off from the glacier could influence global sea level rise.

The decline of Jakobshavn Isbrae between 1850 and 2010 has been well-documented through aerial photographs and satellite photographs by UB Associate Professor of Geology Bea Csatho, which show the ice shrinking rapidly from west to east along a narrow fjord.

To reconstruct the glacier's advance from east to west during earlier, cooler years, Briner and his colleagues examined sediment samples from Glacial Lake Morten and Iceboom Lake, two glacier-fed lakes that sit along the glacier's path of expansion.

As Jakobshavn Isbrae expanded seaward, it reached Glacial Lake Morten first, damming one side of the lake with ice and filling the basin, previously a tundra-covered valley, with meltwater.

To pinpoint the time in history when this happened, the researchers counted annual layers of overlying glacial sediments and used radiocarbon dating to analyze plant fossils at the lake bottom (the last vestiges of the old tundra). The team's conclusion: Glacial Lake Morten formed between 1795 and 1800.

An analysis of sediment layers from the bottom of Iceboom Lake showed that Jakobshavn Isbrae reached Iceboom lake about 20 or 25 years later, around 1820.

Jakobshavn Isbrae's rate of expansion from Glacial Lake Morten to Iceboom Lake, as documented by the UB team, matched the glacier's rate of retreat between those two points. (Aerial imagery shows Iceboom Lake draining around 1965 and Glacial Lake Morten draining between 1986 and 1991.)


Story Source:

The above story is based on materials provided by University at Buffalo. Note: Materials may be edited for content and length.


Journal Reference:

  1. J.P. Briner, N.E. Young, E.K. Thomas, H.A.M. Stewart, S. Losee, S. Truex. Varve and radiocarbon dating support the rapid advance of Jakobshavn Isbrζ during the Little Ice Age. Quaternary Science Reviews, 2011; DOI: 10.1016/j.quascirev.2011.05.017

Cite This Page:

University at Buffalo. "Fast-shrinking Greenland glacier experienced rapid growth during cooler times." ScienceDaily. ScienceDaily, 15 July 2011. <www.sciencedaily.com/releases/2011/07/110714141333.htm>.
University at Buffalo. (2011, July 15). Fast-shrinking Greenland glacier experienced rapid growth during cooler times. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2011/07/110714141333.htm
University at Buffalo. "Fast-shrinking Greenland glacier experienced rapid growth during cooler times." ScienceDaily. www.sciencedaily.com/releases/2011/07/110714141333.htm (accessed September 18, 2014).

Share This



More Earth & Climate News

Thursday, September 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) — Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) — A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Researchers Explore Shipwrecks Off Calif. Coast

Researchers Explore Shipwrecks Off Calif. Coast

AP (Sep. 16, 2014) — Federal researchers are exploring more than a dozen underwater sites where they believe ships sank in the treacherous waters west of San Francisco in the decades following the Gold Rush. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Isolated N. Korea Asks For International Help With Volcano

Isolated N. Korea Asks For International Help With Volcano

Newsy (Sep. 16, 2014) — Mount Paektu volcano in North Korea is showing signs of life and there's not much known about it. 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