Nav: Home

Domes of frozen methane may be warning signs for new blow-outs

June 05, 2017

The results are published in PNAS.

"Every year we go back to the dome area with our research vessel, and every year I am anxious to see if one of these domes has become a crater," says lead author of the study Pavel Serov, PhD candidate at CAGE at UiT The Arctic University of Norway.

These domes are the present-day analogue to what scientists think preceded the craters found in the near-by area, which were recently reported in Science. The craters were formed as the ice sheet retreated from the Barents Sea during the deglaciation some 12.000 years ago.

At the time, 2km thick ice-cover loaded what now is the ocean floor with heavy weight. Under the ice sheet the methane became stored as hydrate, a solid form of frozen methane.

"We believe that one step before the craters are created, you get these domes. They are mounds of hydrates, technically we call them gas hydrate pingos. They are hydrate and methane saturated relics of the last ice-age. They haven't collapsed yet. And the reason is a matter of narrow margins" states Serov.

20 meters from the brink of collapse

The dome area is situated on the Arctic Ocean floor just north of the craters. It is deeper, but not by much. The domes are found some 20 meters deeper. Essentially the height of the Buckingham Palace keeps these methane domes from blowing out the gas and becoming craters.

"Hydrates are stable in low temperatures and under high pressure. So, the pressure of 390 meters of water above is presently keeping them stabilised. But the methane is bubbling from these domes. This is actually one of the most active methane seep sites that we have mapped in the Arctic Ocean. Some of these methane flares extend almost to the sea surface" says Serov.

He is reluctant to speculate as to how much methane may be released into the ocean should the domes collapse entirely and abruptly. It is not possible to predict when it may happen either. But every sediment core collected in the area is full of hydrates.

This is actually the first time that domes such as these have been found outside of the permafrost areas.

More stable than in permafrost

However unstable these domes on the Arctic Ocean floor may be, they are still more stable than the pingos found in sub- sea permafrost in Canadian and Russian Arctic.

"The gas hydrate pingos in permafrost are formed because of the low temperatures. But the water-depth that supports gas hydrates in sub-sea permafrost is only 40 to 50 meters. There is no significant pressure there to keep them in check. Sub-seabed permafrost is deteriorating constantly and quickly" notes Serov.

Even though they are more stable than the permafrost pingos, the Barents Sea domes are on the limit of their existence.

"A relatively small change in the water temperature can destabilise these hydrates fairly quickly. We were actually very lucky to observe them at this point. And we will probably be able to observe significant changes to these domes during our lifetime."
-end-


CAGE - Center for Arctic Gas Hydrate, Climate and Environment

Related Methane Articles:

Microorganisms reduce methane release from the ocean
Bacteria in the Pacific Ocean remove large amounts of the greenhouse gas methane.
Origin of massive methane reservoir identified
New research provides evidence of the formation and abundance of abiotic methane -- methane formed by chemical reactions that don't involve organic matter -- on Earth and shows how the gases could have a similar origin on other planets and moons, even those no longer home to liquid water.
Methane not released by wind on Mars, experts find
New study rules out wind erosion as the source of methane gas on Mars and moves a step closer to answering the question of whether life exists on other planets.
Unexpected culprit -- wetlands as source of methane
Knowing how emissions are created can help reduce them.
Methane-consuming bacteria could be the future of fuel
Northwestern University researchers have found that the enzyme responsible for the methane-methanol conversion in methanotrophic bacteria catalyzes the reaction at a site that contains just one copper ion.
New measurement method for radioactive methane
The method developed by Juho Karhu in his PhD thesis work is a first step towards creating a precise measuring device.
New key players in the methane cycle
Methane is not only a powerful greenhouse gas, but also a source of energy.
Diffusing the methane bomb: We can still make a difference
The Arctic is warming twice as fast as the rest of the planet, causing the carbon containing permafrost that has been frozen for tens or hundreds of thousands of years to thaw and release methane into the atmosphere, thereby contributing to global warming.
China not 'walking the walk' on methane emissions
In China, regulations to reduce methane emissions from coal mining took full effect in 2010 and required methane to be captured or to be converted into carbon dioxide.
Interpreting new findings of methane on Mars
New data from the Mars Science Laboratory demonstrating the presence of methane presents novel challenges to explain how it was formed and what it suggests about the potential for life to exist or be supported on Mars.
More Methane News and Methane Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.