Featured Research

from universities, journals, and other organizations

Potential methane reservoirs beneath Antarctica

Date:
August 29, 2012
Source:
University of Bristol
Summary:
The Antarctic Ice Sheet could be an overlooked but important source of methane, a potent greenhouse gas, according to new research.

Blocks of ice containing subglacial sediments were extracted from the margins of several glaciers and used by the authors in long term incubation experiments aimed at detecting subglacial methane production.
Credit: Image by E. Lawson

The Antarctic Ice Sheet could be an overlooked but important source of methane, a potent greenhouse gas, according to research published August 29 in Nature and conducted by an international team led by Professor Jemma Wadham from the University of Bristol's School of Geographical Sciences.

The new study demonstrates that old organic matter in sedimentary basins located beneath the Antarctic Ice Sheet may have been converted to methane by micro-organisms living under oxygen-deprived conditions. The methane could be released to the atmosphere if the ice sheet shrinks and exposes these old sedimentary basins.

The researchers estimate that 50 per cent of the West Antarctic Ice Sheet (1 million km2) and 25 per cent of the East Antarctic Ice Sheet (2.5 million km2) overlies preglacial sedimentary basins, containing about 21,000 billion tonnes of organic carbon.

Team leader, Professor Wadham said: "This is an immense amount of organic carbon, more than ten times the size of carbon stocks in northern permafrost regions. Our laboratory experiments tell us that these sub-ice environments are also biologically active, meaning that this organic carbon is probably being metabolised to carbon dioxide and methane gas by microbes."

The researchers then numerically simulated the accumulation of methane in Antarctic sedimentary basins using an established one-dimensional hydrate model. They found that sub-ice conditions favour the accumulation of methane hydrate (that is, methane trapped within a structure of water molecules, forming a solid similar to regular ice).

They also calculated that the potential amount of methane hydrate and free methane gas beneath the Antarctic Ice Sheet could be up to 400 billion tonnes (that is, 400 Pg of carbon), a similar order of magnitude to some estimates made for Arctic permafrost. The predicted shallow depth of these potential reserves also makes them more susceptible to climate forcing than other methane hydrate reserves on Earth.

Dr Sandra Arndt, a NERC fellow at the University of Bristol who conducted the numerical modelling, said: "It's not surprising that you might expect to find significant amounts of methane hydrate trapped beneath the ice sheet. Just like in sub-seafloor sediments, it is cold and pressures are high which are important conditions for methane hydrate formation."

If substantial methane hydrate and gas are present beneath the Antarctic Ice Sheet, methane release during episodes of ice-sheet collapse could act as a positive feedback on global climate change during past and future ice-sheet retreat.

Professor Slawek Tulaczyk, glaciologist from the University of California, Santa Cruz, said: "Our study highlights the need for continued scientific exploration of remote sub-ice environments in Antarctica, because they may have far greater impact on Earth's climate system than we have appreciated in the past."

This research is a collaborative venture between the University of Bristol (UK), the University of California, Santa Cruz (US), the University of Alberta, Edmonton (Canada) and the University of Utrecht (The Netherlands).

It was funded principally by the Natural Environment Research Council (UK) and the Leverhulme Trust (UK), with additional funds from the National Science Foundation (US), the Natural Science and Engineering Research Council of Canada and the Netherlands Organisation for Scientific Research (NWO).


Story Source:

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


Journal Reference:

  1. J. L. Wadham, S. Arndt, S. Tulaczyk, M. Stibal, M. Tranter, J. Telling, G. P. Lis, E. Lawson, A. Ridgwell, A. Dubnick, M. J. Sharp, A. M. Anesio, C. E. H. Butler. Potential methane reservoirs beneath Antarctica. Nature, 2012; 488 (7413): 633 DOI: 10.1038/nature11374

Cite This Page:

University of Bristol. "Potential methane reservoirs beneath Antarctica." ScienceDaily. ScienceDaily, 29 August 2012. <www.sciencedaily.com/releases/2012/08/120829131628.htm>.
University of Bristol. (2012, August 29). Potential methane reservoirs beneath Antarctica. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2012/08/120829131628.htm
University of Bristol. "Potential methane reservoirs beneath Antarctica." ScienceDaily. www.sciencedaily.com/releases/2012/08/120829131628.htm (accessed August 22, 2014).

Share This




More Earth & Climate News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Microbrewery Chooses Special Can for Its Beer

Microbrewery Chooses Special Can for Its Beer

AP (Aug. 22, 2014) — Aluminum giant, Novelis, has partnered with Red Hare Brewing Company to introduce the first certified high-content recycled beverage can. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Farm Resurgence Grows With Younger Crowd

Farm Resurgence Grows With Younger Crowd

AP (Aug. 22, 2014) — New England farms are seeing a surge in younger farm hands as the 'buy local' food movement grows across the country. (Aug. 22) Video provided by AP
Powered by NewsLook.com
California Drought Stings Honeybees, Beekeepers

California Drought Stings Honeybees, Beekeepers

AP (Aug. 21, 2014) — California's record drought is hurting honey supplies and raising prices for consumers. The lack of rainfall means fewer crops and wildflowers that provide the nectar bees need to make honey. (Aug. 21) Video provided by AP
Powered by NewsLook.com
Thousands Of Species Found In Lake Under Antarctic Ice

Thousands Of Species Found In Lake Under Antarctic Ice

Newsy (Aug. 20, 2014) — A U.S. team found nearly 4,000 species in a subglacial lake that hasn't seen sunlight in millennia, showing life can thrive even under the ice. 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:

More Coverage


Large Methane Reservoirs Beneath Antarctic Ice Sheet, Study Suggests

Aug. 29, 2012 — The Antarctic Ice Sheet could be an overlooked but important source of methane, a potent greenhouse gas, according to a new ... read more
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