Natalia Shakhova on methane in the East Siberian Arctic Shelf

Methane in the East Siberian Arctic Shelf (2017)

May 23, 2017

The East Siberian Arctic Shelf has received more attention in recent years in regards to a potential contribution of the greenhouse gas methane, for the global methane budget, from several different sources. However, more studies are required to better constrain this potential accelerator of ongoing climate change.


Natalia Shakhova (2014), via Max Wilbert https://www.youtube.com/watch?v=xHziS...

Natalia Shakhova (2010), .. methane stores destabilizing, venting https://www.youtube.com/watch?v=eD8hU...

Study: The origin of methane in the East Siberian Arctic Shelf unraveled (2017)http://www.biogeosciences.net/14/2283...

Review: The interaction of climate change and methane hydrates (2017)http://onlinelibrary.wiley.com/doi/10... and https://www.usgs.gov/news/gas-hydrate...

Rune Pettersen, burn under ice methane in the dark https://www.youtube.com/watch?v=ooAbo...

Methane seep from lake (2012) https://www.youtube.com/watch?v=OANRd...

New Source Of Methane Discovered In The Arctic Ocean https://cage.uit.no/news/new-source-m...

Figure of 300 GTn of fossil fuel emissions via An Arctic methane worst-case scenariohttp://www.realclimate.org/index.php/...

Image 800,000 years of methane (EPA) https://commons.wikimedia.org/wiki/Fi...

Images Methane bubbles collect under the ice (Natalia Shakhova) https://news.uaf.edu/ESAS2013

Underwater bubble sounds https://www.freesound.org/people/Sclo...

Water bubble video clip https://pixabay.com/en/videos/bubbles...

Sound effects via http://Soundmorph.com and http://EpicStockMedia.com

Related: Ocean Waters Above Methane Seeps Absorb Large Amounts Of Co2https://cage.uit.no/news/ocean-waters...

Blooming Algae Could Accelerate Arctic Warming http://www.climatecentral.org/news/al...

The origin of methane in the East Siberian Arctic Shelf unraveled with triple isotope analysis

http://www.biogeosciences.net/14/2283/2017/

Célia J. Sapart1,2, Natalia Shakhova3,4, Igor Semiletov3,4,5, Joachim Jansen1,6, Sönke Szidat7, Denis Kosmach5, Oleg Dudarev5, Carina van der Veen1, Matthias Egger8, Valentine Sergienko9, Anatoly Salyuk5, Vladimir Tumskoy10, Jean-Louis Tison2, and Thomas Röckmann11Institute for Marine and Atmospheric research Utrecht (IMAU), Utrecht University, Princetonplein 5, 3584CC Utrecht, the Netherlands

2Laboratoire de glaciologie, Universtié Libre de Bruxelles (ULB), Avenue Roosevelt 50, 1050 Brussels, Belgium3University Alaska Fairbanks, International Arctic Research Center, 930 Koyukuk Drive, Fairbanks, AK 99775, USA

4Tomsk Polytechnic University, 30 Prospect Lenina, Tomsk, Russia
5Russian Academy of Sciences, Far Eastern Branch, V.I. Il'ichov Pacific Ocenological Institute, 43 Baltiyskaya street, Vladivostok 690041, Russia
6Department of Geological Sciences and Bolin Centre for Climate Research, Stockholm University, Svante Arrhenius väg 8, SE 114 18, Stockholm, Sweden
7Department of Chemistry and Biochemistry & Oeschger Centre for Climate Change Research, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
8Center for Geomicrobiology, Department of Bioscience, Aarhus University, Ny Munkegade 114, 8000 Aarhus, Denmark

9Russian Academy of Sciences, Far Eastern Branch, Institute of Chemistry, 159 Prospect 100-letiya Vladivostoka, Vladivostok 690022, Russia
10Moscow State University, 1 Leninskie Gori, 119991, Moscow, Russia

Received: 31 Aug 2016 – Discussion started: 07 Sep 2016
Revised: 30 Jan 2017 – Accepted: 09 Mar 2017 – Published: 05 May 2017

Abstract. The Arctic Ocean, especially the East Siberian Arctic Shelf (ESAS), has been proposed as a significant source of methane that might play an increasingly important role in the future. However, the underlying processes of formation, removal and transport associated with such emissions are to date strongly debated.

CH4 concentration and triple isotope composition were analyzed on gas extracted from sediment and water sampled at numerous locations on the shallow ESAS from 2007 to 2013. We find high concentrations (up to 500 µM) of CH4 in the pore water of the partially thawed subsea permafrost of this region. For all sediment cores, both hydrogen and carbon isotope data reveal the predominant occurrence of CH4 that is not of thermogenic origin as it has long been thought, but resultant from microbial CH4 formation. At some locations, meltwater from buried meteoric ice and/or old organic matter preserved in the subsea permafrost were used as substrates. Radiocarbon data demonstrate that the CH4 present in the ESAS sediment is of Pleistocene age or older, but a small contribution of highly 14C-enriched CH4, from unknown origin, prohibits precise age determination for one sediment core and in the water column. Our sediment data suggest that at locations where bubble plumes have been observed, CH4 can escape anaerobic oxidation in the surface sediment.Citation: Sapart, C. J., Shakhova, N., Semiletov, I., Jansen, J., Szidat, S., Kosmach, D., Dudarev, O., van der Veen, C., Egger, M., Sergienko, V., Salyuk, A., Tumskoy, V., Tison, J.-L., and Röckmann, T.: The origin of methane in the East Siberian Arctic Shelf unraveled with triple isotope analysis, Biogeosciences, 14, 2283-2292, doi:10.5194/bg-14-2283-2017, 2017.