气候变化领域集成服务门户(CCPortal): Source apportionment of methane escaping the subsea permafrost system in the outer Eurasian Arctic Shelf

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DOI	10.1073/pnas.2019672118
	Source apportionment of methane escaping the subsea permafrost system in the outer Eurasian Arctic Shelf
	Steinbach J.; Holmstrand H.; Shcherbakova K.; Kosmach D.; Brüchert V.; Shakhova N.; Salyuk A.; Sapart C.J.; Chernykh D.; Noormets R.; Semiletov I.; Gustafsson Ö.
发表日期	2021
ISSN	00278424
卷号	118 期号:10
英文摘要	The East Siberian Arctic Shelf holds large amounts of inundated carbon and methane (CH4). Holocene warming by overlying seawater, recently fortified by anthropogenic warming, has caused thawing of the underlying subsea permafrost. Despite extensive observations of elevated seawater CH4 in the past decades, relative contributions from different subsea compartments such as early diagenesis, subsea permafrost, methane hydrates, and underlying thermogenic/ free gas to these methane releases remain elusive. Dissolved methane concentrations observed in the Laptev Sea ranged from 3 to 1,500 nM (median 151 nM; oversaturation by ∼3,800%). Methane stable isotopic composition showed strong vertical and horizontal gradients with source signatures for two seepage areas of δ13C-CH4 = (−42.6 ± 0.5)/(−55.0 ± 0.5) % and δD-CH4 = (−136.8 ± 8.0)/(−158.1 ± 5.5) %, suggesting a thermogenic/ natural gas source. Increasingly enriched δ13C-CH4 and δD-CH4 at distance from the seeps indicated methane oxidation. The Δ14C-CH4 signal was strongly depleted (i.e., old) near the seeps (−993 ± 19/−1050 ± 89%). Hence, all three isotope systems are consistent with methane release from an old, deep, and likely thermogenic pool to the outer Laptev Sea. This knowledge of what subsea sources are contributing to the observed methane release is a prerequisite to predictions on how these emissions will increase over coming decades and centuries. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Arctic; Carbon cycle/climate change; Isotopes/radiocarbon; Methane; Subsea permafrost
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180421
作者单位	Department of Environmental Science, Stockholm University, Stockholm, 106 91, Sweden; Department of Geological Sciences, Stockholm University, Stockholm, 106 91, Sweden; Bolin Centre for Climate Research, Stockholm University, Stockholm, 106 91, Sweden; V.I. Il’ichev Pacific Oceanological Institute, Far Eastern Branch of the Russian Academy of Sciences, Vladivostok, 690041, Russian Federation; Institute of Ecology, Higher School of Economics, Moscow, 101000, Russian Federation; International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, AK 99775, United States; Scientific Centre Moscow State University-Geophysics, Moscow, 119991, Russian Federation; Laboratoire de Glaciologie, Université Libre de Bruxelles, Brussels, 1050, Belgium; Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, 3584 CC, Netherlands; Department of Arctic Geology, University Centre Svalbard, Longyearbyen, N-9171, Norway
推荐引用方式 GB/T 7714	Steinbach J.,Holmstrand H.,Shcherbakova K.,et al. Source apportionment of methane escaping the subsea permafrost system in the outer Eurasian Arctic Shelf[J],2021,118(10).
APA	Steinbach J..,Holmstrand H..,Shcherbakova K..,Kosmach D..,Brüchert V..,...&Gustafsson Ö..(2021).Source apportionment of methane escaping the subsea permafrost system in the outer Eurasian Arctic Shelf.Proceedings of the National Academy of Sciences of the United States of America,118(10).
MLA	Steinbach J.,et al."Source apportionment of methane escaping the subsea permafrost system in the outer Eurasian Arctic Shelf".Proceedings of the National Academy of Sciences of the United States of America 118.10(2021).