Featured Research

from universities, journals, and other organizations

Disappearing snow increases risk of collapsing ice shelves in Antarctica

Date:
January 30, 2014
Source:
British Antarctic Survey
Summary:
A number of floating ice shelves in Antarctica are at risk of disappearing entirely in the next 200 years, as global warming reduces their snow cover. Their collapse would enhance the discharge of ice into the oceans and increase the rate at which sea-level rises. A rapid reduction of greenhouse gas emissions could save a number of these ice shelves, researchers say.

A number of floating ice shelves in Antarctica are at risk of disappearing entirely in the next 200 years, as global warming reduces their snow cover. Their collapse would enhance the discharge of ice into the oceans and increase the rate at which sea-level rises. A rapid reduction of greenhouse gas emissions could save a number of these ice shelves, researchers at Utrecht University and the British Antarctic Survey say in a new paper published today in the Journal of Glaciology.

Back in 1995 and 2002, two floating ice shelves in the north of the Antarctic Peninsula (Larsen A and B) suddenly collapsed -- each event occurred in a matter of weeks.

Dr Peter Kuipers Munneke, the paper's lead author, said: "This was a spectacular event, especially when you imagine the size of these ice shelves, which are several hundreds of metres thick, and have been in place for over 10,000 years."

The team of researchers suspected that the disappearance of the snow layer on top of the ice shelves could be an important precursor for shelf collapse. Their calculations confirm this hypothesis, and show that many more ice shelves could disappear in the next 200 years.

The scientists believed the snow layer plays an important role in regulating the effect of meltwater lakes on the ice shelves.

As long as the snow layer is sufficiently thick and cold, all meltwater can sink into the snow and refreeze. But in a warmer climate, the amount of meltwater increases, and the snow layers become thinner.

As a result, meltwater can no longer refreeze and forms large lakes on the surface of the ice shelves. The water drains through cracks and faults, causing them to widen until they become so wide and deep that the entire ice shelf disintegrates.

After their collapse, ice shelves can no longer provide resistance to the flow of the glaciers previously feeding them. As a result, the glacier flow accelerates significantly, contributing to an increase in sea-level rise.

The researchers performed calculations that show how this process may evolve over the next 200 years, using two different climate scenarios.

Dr Kuipers Munnekke said: "If we continue to burn fossil fuels at the current rate, almost all ice shelves in the Antarctic Peninsula will be under threat of collapse in the next 200 years. Only the two largest ones seem to be safe. Even in the much colder eastern part of Antarctica, some ice shelves could disintegrate. If we manage to keep global warming below the European Union target of 2oC, more than half of the ice shelves could be saved, compared to no action taken on emissions reductions."

The study received financial support from the European Union's four-year ice2sea project. Prof. David Vaughan said "We've been observing ice-shelf retreat around the Antarctic Peninsula since the early 1990s, but for the first time this model provides a strong basis for the prediction of future changes, which is a major step forward in understanding future sea-level changes."


Story Source:

The above story is based on materials provided by British Antarctic Survey. Note: Materials may be edited for content and length.


Journal Reference:

  1. Peter Kuipers Munneke, Stefan R.m. Ligtenberg, Michiel R. Van Den Broeke, David G. Vaughan. Firn air depletion as a precursor of Antarctic ice-shelf collapse. Journal of Glaciology, 2014; 60 (220): 205 DOI: 10.3189/2014JoG13J183

Cite This Page:

British Antarctic Survey. "Disappearing snow increases risk of collapsing ice shelves in Antarctica." ScienceDaily. ScienceDaily, 30 January 2014. <www.sciencedaily.com/releases/2014/01/140130040834.htm>.
British Antarctic Survey. (2014, January 30). Disappearing snow increases risk of collapsing ice shelves in Antarctica. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2014/01/140130040834.htm
British Antarctic Survey. "Disappearing snow increases risk of collapsing ice shelves in Antarctica." ScienceDaily. www.sciencedaily.com/releases/2014/01/140130040834.htm (accessed September 2, 2014).

Share This




More Earth & Climate News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Iceland Lowers Aviation Alert on Volcano

Iceland Lowers Aviation Alert on Volcano

AFP (Sep. 1, 2014) Iceland has lowered its aviation alert on its largest volcano after a fresh eruption on a nearby lava field prompted authorities to enforce a flight ban for several hours. Duration: 01:07 Video provided by AFP
Powered by NewsLook.com
Lightning Hurts 3 on NYC Beach

Lightning Hurts 3 on NYC Beach

AP (Sep. 1, 2014) A lightning strike injured three people on a New York City beach on Sunday. The storms also delayed flights and interrupted play at the US Open tennis tournament. (Sept. 1) Video provided by AP
Powered by NewsLook.com
Thailand Totters Towards Waste Crisis

Thailand Totters Towards Waste Crisis

AFP (Sep. 1, 2014) Fears are mounting in Bangkok that poor planning and lax law enforcement are tipping Thailand towards a waste crisis. Duration: 01:21 Video provided by AFP
Powered by NewsLook.com
Melting Ice Shelves Drive Rapid Antarctic Sea Level Rise

Melting Ice Shelves Drive Rapid Antarctic Sea Level Rise

Newsy (Sep. 1, 2014) A study of almost 20 years' worth of satellite images shows Antarctic sea levels are on the rise as ice shelves continue to melt. 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