气候变化领域集成服务门户(CCPortal): Sub-permafrost methane seepage from open-system pingos in Svalbard

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DOI	10.5194/tc-14-3829-2020
	Sub-permafrost methane seepage from open-system pingos in Svalbard
	Hodson A.J.; Nowak A.; Hornum M.T.; Senger K.; Redeker K.; Christiansen H.H.; Jessen S.; Betlem P.; Thornton S.F.; Turchyn A.V.; Olaussen S.; Marca A.
发表日期	2020
ISSN	19940416
起始页码	3829
结束页码	3842
卷号	14 期号:11
英文摘要	Methane release from beneath lowland permafrost represents an important uncertainty in the Arctic greenhouse gas budget. Our current knowledge is arguably best developed in settings where permafrost is being inundated by rising sea level, which means much of the methane is oxidised in the water column before it reaches the atmosphere. Here we provide a different process perspective that is appropriate for Arctic fjord valleys where local deglaciation causes isostatic uplift to out pace rising sea level. We describe how the uplift induces permafrost aggradation in former marine sediments, whose pressurisation results in methane escape directly to the atmosphere via groundwater springs. In Adventdalen, central Spitsbergen, we show how the springs are historic features responsible for the formation of open-system pingos and capable of discharging brackish waters enriched with high concentrations of mostly biogenic methane (average 18 mgL-1). Thermodynamic calculations show that the methane concentrations sometimes marginally exceed the solubility limit for methane in water at 0 C (41mgL-1). Year-round emissions from the pingos are described. During winter, rapid methane loss to the atmosphere occurs following outburst events from beneath an ice blister. During summer, highly variable emissions occur due to complex surface processes at the seepage point and its inundation by surface runoff. In spite of this complexity, our observations confirm that sub-permafrost methane migration deserves more attention for the improved forecasting of Arctic greenhouse gas emissions. © 2020 Copernicus GmbH. All rights reserved.
英文关键词	deglaciation; fjord; greenhouse gas; methane; outburst; permafrost; seepage; Adventdalen; Arctic; Arctic; Spitsbergen; Svalbard; Svalbard and Jan Mayen
语种	英语
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202100
作者单位	Department of Arctic Geology, University Centre in Svalbard (UNIS), Longyearbyen, 9171, Norway; Department of Environmental Science, Western Norway University of Applied Sciences, Røyrgata 6, Sogndal, 6856, Norway; Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen K, Copenhagen, 1350, Denmark; Department of Biology, University of York, York, YO10 5DD, United Kingdom; Department of Civil and Structural Engineering, University of Sheffield, Sheffield, S10 2TN, United Kingdom; Department of Earth Sciences, University of Cambridge, Cambridge, CB2 3EQ, United Kingdom; School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
推荐引用方式 GB/T 7714	Hodson A.J.,Nowak A.,Hornum M.T.,et al. Sub-permafrost methane seepage from open-system pingos in Svalbard[J],2020,14(11).
APA	Hodson A.J..,Nowak A..,Hornum M.T..,Senger K..,Redeker K..,...&Marca A..(2020).Sub-permafrost methane seepage from open-system pingos in Svalbard.Cryosphere,14(11).
MLA	Hodson A.J.,et al."Sub-permafrost methane seepage from open-system pingos in Svalbard".Cryosphere 14.11(2020).