Study: Arctic seafloor methane releases double previous estimates

 
Photo courtesy of Natalia Shakhova Methane burns as it escapes through a hole in the ice in a lagoon above the East Siberian Arctic Shelf.

Photo courtesy of Natalia Shakhova
Methane burns as it escapes through a hole in the ice in a lagoon above the East Siberian Arctic Shelf.

Marmian Grimes
907-474-7902
11/24/13

The seafloor off the coast of Northern Siberia is releasing more than twice the amount of methane as previously estimated, according to new research results published in the Nov. 24 edition of the journal Nature Geoscience.

The East Siberian Arctic Shelf is venting at least 17 teragrams of the methane into the atmosphere each year. A teragram is equal to 1 million tons.

“It is now on par with the methane being released from the arctic tundra, which is considered to be one of the major sources of methane in the Northern Hemisphere,” said Natalia Shakhova, one of the paper’s lead authors and a scientist at the University of Alaska Fairbanks. “Increased methane releases in this area are a possible new climate-change-driven factor that will strengthen over time.”

Methane is a greenhouse gas more than 30 times more potent than carbon dioxide. On land, methane is released when previously frozen organic material decomposes. In the seabed, methane can be stored as a pre-formed gas or asmethane hydrates. As long as the subsea permafrost remains frozen, it forms a cap, effectively trapping the methane beneath. However, as the permafrost thaws, it develops holes, which allow the methane to escape. These releases can be larger and more abrupt than those that result from decomposition.

The findings are the latest in an ongoing international research project led by Shakhova and Igor Semiletov, both researchers at the UAF International Arctic Research Center. Their twice-yearly arctic expeditions have revealed that the subsea permafrost in the area has thawed much more extensively than previously thought, in part due to warming water near the bottom of the ocean. The warming has created conditions that allow the subsea methane to escape in much greater amounts than their earlier models estimated. Frequent storms in the area hasten its release into the atmosphere, much in the same way stirring a soda releases the carbonation more quickly.

“Results of this study represent a big step forward toward improving our understanding of methane emissions from the East Siberian Arctic Shelf,” said Shakhova. She noted that while the ESAS is unusual in its expansive and shallow nature, the team’s findings there speak to the need for further exploration of the subsea Arctic. “I believe that all other arctic shelf areas are significantly underestimated and should be paid very careful attention to.”

Methane bubbles collect under the ice.

Photo courtesy of Natalia Shakhova
Methane bubbles collect under the ice.

The East Siberian Arctic Shelf is a methane-rich area that encompasses more than 2 million square kilometers of seafloor in the Arctic Ocean. It is more than three times as large as the nearby Siberian wetlands, which have been considered the primary Northern Hemisphere source of atmospheric methane. Previous estimates performed for the ESAS suggested that the area was releasing 8 teragrams of methane into the atmosphere yearly.

During field expeditions, the research team used a variety of techniques—including sonar and visual images of methane bubbles in the water, air and water sampling, seafloor drilling and temperature readings—to determine the conditions of the water and permafrost, as well as the amount of methane being released.

Methane is an important factor in global climate change, because it so effectively traps heat. As conditions warm, global research has indicated that more methane is released, which then stands to further warm the planet. Scientists call this phenomenon a positive feedback loop.

“We believe that the release of methane from the Arctic, and in particular this part of the Arctic, could impact the entire globe,” Shakhova said. “We are trying to understand the actual contribution of the ESAS to the global methane budget and how that will change over time.”

Members of the scientific field expedition drill through the ice and into the seafloor of the East Siberian Arctic Shelf.

Photo courtesy of Natalia Shakhova
Members of the scientific field expedition drill through the ice and into the seafloor of the East Siberian Arctic Shelf.

Shakhova and Semiletov are also affiliated with the Pacific Oceanological Institute at the Russian Academy of Sciences, Far Eastern Branch, as are research team members Anatoly Salyuk, Denis Kosmach and Denis Chernykh. Other members of the research team include Dmitry Nicolsky of the UAF Geophysical Institute; co-lead author Ira Leifer of the Marine Sciences Institute at the University of California, Santa Barbara and Bubbleology Research International; Valentin Sergienko of the Institute of Chemistry at the Russian Academy of Sciences, Far Eastern Branch; Chris Stubbs of the Marine Sciences Institute at the University of California, Santa Barbara; Vladimir Tumskoy of Moscow State University; and Örjan Gustafsson of the Department of Applied Environmental Science and Bolin Centre for Climate Research, Stockholm University.

NOTE TO EDITORS: Photos of methane bubbles in the sea and fieldwork are available for download at http://uafcornerstone.net/ESAS2013/

MG/11-24-13/137-14

 

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9 Comments

  • So can this methane be cheaply captured and used as an alt fuel for autos?

    We need affordable gas again, soon.

     
    • Natalia Shakhova

      I believe, this gas could be recovered from the Russian Arctic Shelf and used as fuel – this is exactly what American and Canadian energy companies plan to do on their shelves. The problem is that it is not cheap for any country. In Russia, there are such plans too.

       
  • Thom Foote

    But Warsaw resulted in “hopeful” progress toward addressing the coming crisis. Don’t worry Paris is coming and everything will be all right.

     
  • Re: sea floor methane
    I wonder if the ‘soda stir’ technique could be used to ‘mine’ the methane.
    1. a inverted cup with 2 propeller blades: one above to catch ocean currents and spin an axle, one below: spun by the axle to ‘stir’ the bottom
    2. a pipe coming out the top of the cup and going to land, for use in heating, electricity generation etc so it replaces methane that would otherwise be mined by drilling

     
    • Natalia Shakhova

      1. I am afraid that “soda stir” mining technique will only work if we are able to solve two opposing tasks: to hermetically cover the entire 2 million square kilometers of the Siberian Arctic Shelf with some magic material capturing methane, and to make this material to not work as a gigantic sail. Besides, we have to close the Northern Sea Route, which has been in use for more than a century. What do you think?
      2. How many do you think we will need to cover 2 million square kilometers all at once?
      3.This is a good idea – Norwegian do this already on their shelf.

       
  • Bob Paglee (M. Robert Paglee, P.E., NJ (Ret.)

    Reading this initially on WUWT.com made me wonder if that was what makes the Arctic ice less substantial near eastern Siberia so I posted a comment on WattsUpWithThat.com similar to this one.

    Does the methane venting into the Arctic polar sea near eastern Siberia result in underwater warming that reduces the thickness of the ice in the region trending east of Novaya Zemiya Island? Through a slow oxidation process, can methane combine with oxygen dissolved in sea-water to create a little heating that thins the ice where methane is trapped more than elsewhere?

    Maybe you can see this effect from the fascinating animated time-lapse Arctic ice-thickness map by NRL. Here’s the link:

    http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticict_nowcast_anim365d.gif

    Any comments, or is this just a nutty idea? I tried to send it to Prof. Akasofu who is superbly well-informed but I have lost his e-mail address.

     
    • Natalia Shakhova

      I believe that there are few factors that contribute to decrease sea ice coverage in the East Siberian Arctic Shelf (ESAS). First is that this area itself is among those Arctic regions warming up faster than others in the 20th century. Another reason for that is increasing discharge of the Siberian Arctic Rivers (there are 6 rivers bringing their waters to the ESAS – Khatanga, Olenek, Anabar, Lena, Yana, Indigirka and Kolyma). One more reason is that ice formation occurs later nowadays while ice break happens earlier – this serves to decreasing the thickness of the sea ice. Increasing frequency of strong-wind evens serves to destroy ice cover during its formation.
      Regarding the heating effect of methane oxidation in the water column, I can say the following. You are right in that oxidation of methane by microbes is accompanied with energy production. But the problem is that his energy is not coming in to the water – microbes use it for their living cycle.

       
  • Mohideen Ibramsha

    Between leaving the methane to mix with the atmospheric air and burning the methane, burning the methane is environmentally better. But the best option is to collect the methane and use it as fuel.

    The URL gives the details of a 1.5 mil thick clear plastic sheet that is 20 feet wide and 200 feet long covering 4,000 sq ft of area. By using 20 such sheets we cover a square of 200 feet by 200 feet with an area of 40,000 sq ft. A boat could be used for each 40,000 sq ft to collect the methane that emerges in 40,000 sq ft, compress the same and transport it to the shore.

    I hope the industry to collect this methane coming out of the thawing permafrost would evolve converting a climate scare to a climate boon.

     
  • Natalia Shakhova

    I agree that recovering methane is a better option. The way to do it is invented by Norwegians – they do sort of horizontal drilling from on-shore to recover methane from the seabed. Regarding capturing methane by sheets using boats, please, read my comment above.

     
 

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