Sub-permafrost methane seepage from open-system pingos in Svalbard
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 colu...
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ftuniveastangl:oai:ueaeprints.uea.ac.uk:77699 2023-05-15T13:05:43+02:00 Sub-permafrost methane seepage from open-system pingos in Svalbard Hodson, Andrew Nowak, Aga Hornum, Mikkel Senger, Kim Redeker, Kelly Christiansen, Hanne H Jessen, Soren Betlem, Peter Thornton, Steve F Turchyn, Alexandra V Olaussen, Snorre Marca, Alina 2020-11-09 application/pdf https://ueaeprints.uea.ac.uk/id/eprint/77699/ https://ueaeprints.uea.ac.uk/id/eprint/77699/1/Published_Version.pdf https://doi.org/10.5194/tc-14-3829-2020 en eng https://ueaeprints.uea.ac.uk/id/eprint/77699/1/Published_Version.pdf Hodson, Andrew, Nowak, Aga, Hornum, Mikkel, Senger, Kim, Redeker, Kelly, Christiansen, Hanne H, Jessen, Soren, Betlem, Peter, Thornton, Steve F, Turchyn, Alexandra V, Olaussen, Snorre and Marca, Alina (2020) Sub-permafrost methane seepage from open-system pingos in Svalbard. The Cryosphere, 14 (11). pp. 3829-3842. ISSN 1994-0440 doi:10.5194/tc-14-3829-2020 cc_by CC-BY Article PeerReviewed 2020 ftuniveastangl https://doi.org/10.5194/tc-14-3829-2020 2023-01-30T21:53:52Z 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. Article in Journal/Newspaper Adventdalen Arctic Ice permafrost Svalbard The Cryosphere Spitsbergen University of East Anglia: UEA Digital Repository Arctic Svalbard Adventdalen ENVELOPE(16.264,16.264,78.181,78.181) The Cryosphere 14 11 3829 3842 |
institution |
Open Polar |
collection |
University of East Anglia: UEA Digital Repository |
op_collection_id |
ftuniveastangl |
language |
English |
description |
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. |
format |
Article in Journal/Newspaper |
author |
Hodson, Andrew Nowak, Aga Hornum, Mikkel Senger, Kim Redeker, Kelly Christiansen, Hanne H Jessen, Soren Betlem, Peter Thornton, Steve F Turchyn, Alexandra V Olaussen, Snorre Marca, Alina |
spellingShingle |
Hodson, Andrew Nowak, Aga Hornum, Mikkel Senger, Kim Redeker, Kelly Christiansen, Hanne H Jessen, Soren Betlem, Peter Thornton, Steve F Turchyn, Alexandra V Olaussen, Snorre Marca, Alina Sub-permafrost methane seepage from open-system pingos in Svalbard |
author_facet |
Hodson, Andrew Nowak, Aga Hornum, Mikkel Senger, Kim Redeker, Kelly Christiansen, Hanne H Jessen, Soren Betlem, Peter Thornton, Steve F Turchyn, Alexandra V Olaussen, Snorre Marca, Alina |
author_sort |
Hodson, Andrew |
title |
Sub-permafrost methane seepage from open-system pingos in Svalbard |
title_short |
Sub-permafrost methane seepage from open-system pingos in Svalbard |
title_full |
Sub-permafrost methane seepage from open-system pingos in Svalbard |
title_fullStr |
Sub-permafrost methane seepage from open-system pingos in Svalbard |
title_full_unstemmed |
Sub-permafrost methane seepage from open-system pingos in Svalbard |
title_sort |
sub-permafrost methane seepage from open-system pingos in svalbard |
publishDate |
2020 |
url |
https://ueaeprints.uea.ac.uk/id/eprint/77699/ https://ueaeprints.uea.ac.uk/id/eprint/77699/1/Published_Version.pdf https://doi.org/10.5194/tc-14-3829-2020 |
long_lat |
ENVELOPE(16.264,16.264,78.181,78.181) |
geographic |
Arctic Svalbard Adventdalen |
geographic_facet |
Arctic Svalbard Adventdalen |
genre |
Adventdalen Arctic Ice permafrost Svalbard The Cryosphere Spitsbergen |
genre_facet |
Adventdalen Arctic Ice permafrost Svalbard The Cryosphere Spitsbergen |
op_relation |
https://ueaeprints.uea.ac.uk/id/eprint/77699/1/Published_Version.pdf Hodson, Andrew, Nowak, Aga, Hornum, Mikkel, Senger, Kim, Redeker, Kelly, Christiansen, Hanne H, Jessen, Soren, Betlem, Peter, Thornton, Steve F, Turchyn, Alexandra V, Olaussen, Snorre and Marca, Alina (2020) Sub-permafrost methane seepage from open-system pingos in Svalbard. The Cryosphere, 14 (11). pp. 3829-3842. ISSN 1994-0440 doi:10.5194/tc-14-3829-2020 |
op_rights |
cc_by |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/tc-14-3829-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
11 |
container_start_page |
3829 |
op_container_end_page |
3842 |
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1766392058954645504 |