Subscribe free to our newsletters via your
. 24/7 Space News .


Subscribe free to our newsletters via your




















ICE WORLD
Ice sheets may be hiding vast reservoirs of powerful greenhouse gas
by Staff Writers
Oslo, Norway (SPX) Jan 14, 2016


Pockmarks are scars on the ocean floor, an evidence of gas release. These likely appeared as the ice sheet retreated from the western part of Svalbard, and the area began to submerge in seawater again. They prove that release of methane followed the retreat of the ice sheet. Image courtesy Alexey Portnov/CAGE. For a larger version of this image please go here.

The study indicates that under the frigid weight of Barents Sea Ice sheet, which covered northern Eurasia some 22 000 years ago, significant amounts of methane may have been stored as hydrates in the ground. As the ice sheet retreated, the methane rich hydrates melted, releasing the climate gas into the ocean and atmosphere for millennia.

"Creation of gas hydrates requires high pressure; water; gas - mainly methane - and low temperatures. Nowadays we basically consider two environments suitable for this process to occur: subseabed along the world's continental margins, and permafrost areas on land and off shore. " Says principal author of the study, Dr. Alexey Portnov of CAGE - Centre for Arctic Gas Hydrate, Environment and Climate at UiT The Arctic University of Norway.

Ice sheets - a third process
But this is the first comprehensive study that shows that there is a third process that can create, contain and maintain large amounts of gas hydrates: ice sheets.

"They are heavy, can exert enormous pressure on the ground below. And they are cold, of course. With enough supply of gas and water from below and favorable geological setting you will likely have enormous amounts of gas hydrates contained under modern ice sheets as well".

500-meter thick methane reservoir
The theory that this may be happening beneath the Antarctic ice sheet has been published previously in Nature. CAGE-study is a more comprehensive take on that idea, and shows same processes taking place in the Arctic.

Scientists from CAGE have over time collected wide-ranging observational data offshore western Svalbard in the Arctic Ocean. This made it possible to create robust models for a scenario of subglacial evolution of gas hydrate reservoirs during and after Last Glacial Maximum, or last ice age in layman's terms.

The results of the study indicate that even under conservative estimates of ice thickness a 500-meter thick gas hydrate stability zone existed beneath the ice sheet in the study area. This zone could have served as a methane sink-a reservoir containing immense amounts of the natural greenhouse gas. 1 m3 of gas hydrate contains almost 170 m3 of the greenhouse gas methane.

Rapid melt caused release of methane
During the last ice age the continental margin offshore western Svalbard, was land covered with ice, much as Greenland and Antarctica of today. But as the climate changed, the ice melted over a period of thousands of years, a rapid melt in geological terms.

The scientists have mapped over 1900 pockmarks - gas escape features - on what now is the seafloor in the study area. The age of these pockmarks has in previous studies been estimated as post-glacial, meaning that they appeared after the ice sheet had retreated.

"Pockmarks are evidence of gas release from the ground. We infer that the gas hydrate zone was stable as long as the climate was cold and the ice sheet was stable. Abrupt climate warming caused sheets to melt, decreasing the pressure on the ground and increasing the temperature. This destabilized the hydrates. Methane was released into rising seawater and possibly the atmosphere." says Portnov.

As the ice sheet retreated, the pressure lifted, steadily widening the corridor for major methane release.

Accelerating climate change
Rapid melting of the ice sheets due to global warming, and subsequent sea level rise has long been a concern to scientists.

Methane, being at least 20 times more potent greenhouse gas than CO2, can accelerate the global warming. If the same process of methane storage is occurring under the current ice sheets, there may be a new threat to take into the account when we are discussing ice sheet retreat in the future.

Modern ice sheets will not need thousands of years to melt., The Greenland ice sheet has been losing an estimated 287 billion metric tons per year, states NASA. The continent of Antarctica has been losing about 134 billion metric tons of ice per year since 2002, albeit its ice sheet tells a more complicated story.

"It is difficult to study this processes in modern polar environments. The ice sheets of Greenland and Antarctica are several kilometers thick and examining the ground beneath them is challenging and expensive, nonetheless. But the circumstances that were present in formation of gas hydrate zones in the past are also present today. We need to take that into the account when we are considering the impacts that the rapid melt of the modern ice sheets will have on our future climate" says Portnov.

This finding was published last week in Nature Communications in the paper "Ice-sheet-driven methane storage and release in the Arctic".

.


Related Links
Center for Arctic Gas Hydrate, Climate and Environment
Beyond the Ice Age






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
ICE WORLD
Greenland ice sheet melts more when it's cloudy
Leuven, Belgium (SPX) Jan 13, 2016
Clouds play a bigger role in the melting of the Greenland ice sheet than was previously assumed. Compared to clear skies, clouds enhance the meltwater runoff by a third. Those are the findings of an international study that was coordinated by KU Leuven and published in Nature Communications. Greenland's ice sheet is the second largest ice mass in the world - the largest is Antarctica. The ... read more


ICE WORLD
Momentum builds for creation of 'moon villages'

Chang'e-3 landing site named "Guang Han Gong"

South Korea to launch lunar exploration in 2016, land by 2020

Death rumors of Russian lunar program 'greatly exaggerated' - Deputy PM

ICE WORLD
Rover Rounds Martian Dune to Get to the Other Side

Boulders on a Martian Landslide

NASA suspends March launch of InSight mission to Mars

University researchers test prototype spacesuits at Kennedy

ICE WORLD
Six Orion Milestones to Track in 2016

Gadgets get smarter, friendlier at CES show

Congress to NASA: Hurry up on that 'habitation augmentation module'

NASA Reaches New Heights

ICE WORLD
China's Belt and Road Initiative catches world's imagination: Inmarsat CEO

China launches HD earth observation satellite

Chinese rover analyzes moon rocks: First new 'ground truth' in 40 years

Agreement with Chinese Space Tech Lab Will Advance Exploration Goals

ICE WORLD
British astronaut's first spacewalk set for Jan 15

NASA Delivers New Video Experience On ISS

British astronaut dials wrong number on Xmas call from space

Space Station Receives New Space Tool to Help Locate Ammonia Leaks

ICE WORLD
Arianespace starts year with record order backlog

Russian Space Forces launched 21 spacecraft in 2015

Russian Proton-M Carrier Rocket With Express-AMU1 Satellite Launched

45th Space Wing launches ORBCOMM; historically lands first stage booster

ICE WORLD
Lab discovery gives glimpse of conditions found on other planets

Nearby star hosts closest alien planet in the 'habitable zone'

ALMA reveals planetary construction sites

Monster planet is 'dancing with the stars'

ICE WORLD
China chemical giant to acquire Germany's KraussMaffei

How seashells get their strength

Tech tethers dog lovers remotely to their pets

Thor's hammer to crush materials at 1 million atmospheres




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News








The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.