Permafrost degradation and methane release in the central Laptev Sea
The transition from onshore to offshore permafrost during periods of low relative sea level rise is often the result of coastal retreat. Along the Laptev Sea coastline, ice-rich syngenetic permafrost is particularly susceptible to erosion due to changing climate, and coastal retreat floods about 10...
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University of Lisbon and the University of Évora
2014
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ftawi:oai:epic.awi.de:35772 2024-09-09T19:44:21+00:00 Permafrost degradation and methane release in the central Laptev Sea Overduin, Paul Grigoriev, Mikhail N. Schirrmeister, Lutz Wetterich, Sebastian Nätscher, Valentin Günther, Frank Liebner, Susanne Knoblauch, Christian Hubberten, Hans-Wolfgang 2014-06-18 https://epic.awi.de/id/eprint/35772/ http://www.eucop4.org/ https://hdl.handle.net/10013/epic.43697 unknown University of Lisbon and the University of Évora Overduin, P. orcid:0000-0001-9849-4712 , Grigoriev, M. N. , Schirrmeister, L. orcid:0000-0001-9455-0596 , Wetterich, S. orcid:0000-0001-9234-1192 , Nätscher, V. , Günther, F. orcid:0000-0001-8298-8937 , Liebner, S. , Knoblauch, C. and Hubberten, H. W. (2014) Permafrost degradation and methane release in the central Laptev Sea , 4th European Conference on Permafrost, Evora, 18 June 2014 - 21 June 2014 . hdl:10013/epic.43697 EPIC34th European Conference on Permafrost, Evora, 2014-06-18-2014-06-21Evora, University of Lisbon and the University of Évora Conference notRev 2014 ftawi 2024-06-24T04:09:53Z The transition from onshore to offshore permafrost during periods of low relative sea level rise is often the result of coastal retreat. Along the Laptev Sea coastline, ice-rich syngenetic permafrost is particularly susceptible to erosion due to changing climate, and coastal retreat floods about 10 km2 of permafrost each year. Changes to permafrost immediately after flooding provide an opportunity to study the mechanism of submarine permafrost degradation in general. Recent studies have drawn a link between observed methane release on the Laptev Sea shelf and surmised permafrost degradation. We combine direct observations of permafrost and methane to investigate the possibility of methane release from permafrost as a source. Our studies focus on a site in Buor Khaya Bay in the central Laptev Sea, for which coastal retreat rates have been studied. Following geophysical reconnaissance, we drilled a 52 m deep core in the near-shore zone of the eastern shore of Buor Khaya Bay and measured the permafrost temperature in the resulting borehole. Comparison of the submarine permafrost temperature to temperatures on land reveal warming of permafrost by 8 to 10 °C over a period of less than a millennium. During this time, the top of the ice-bearing permafrost (IBPF) degraded from 0 to 28.8 m b.s.l. at the borehole site, a mean degradation rate of almost 3 cm per year. Geoelectric resistivity measurements corroborate this observation and show a decline of the IBPF with increasing distance from shore. Similar to many other Siberian locations, the deeper permafrost at the study site contained less organic carbon by orders of magnitude when compared to the overlying syngenetic ice complex deposits. The same held true for methane concentrations in the frozen permafrost. Our data suggest that these comparatively low concentrations of methane are oxidized in the sediment column upon thawing. Analyses of the sediment and pore water chemistry demonstrate that sea water is probably advected to the IBPF, which contributes to ... Conference Object Ice laptev Laptev Sea permafrost Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Buor-Khaya ENVELOPE(127.803,127.803,72.287,72.287) Khaya ENVELOPE(135.167,135.167,60.567,60.567) Laptev Sea |
institution |
Open Polar |
collection |
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
The transition from onshore to offshore permafrost during periods of low relative sea level rise is often the result of coastal retreat. Along the Laptev Sea coastline, ice-rich syngenetic permafrost is particularly susceptible to erosion due to changing climate, and coastal retreat floods about 10 km2 of permafrost each year. Changes to permafrost immediately after flooding provide an opportunity to study the mechanism of submarine permafrost degradation in general. Recent studies have drawn a link between observed methane release on the Laptev Sea shelf and surmised permafrost degradation. We combine direct observations of permafrost and methane to investigate the possibility of methane release from permafrost as a source. Our studies focus on a site in Buor Khaya Bay in the central Laptev Sea, for which coastal retreat rates have been studied. Following geophysical reconnaissance, we drilled a 52 m deep core in the near-shore zone of the eastern shore of Buor Khaya Bay and measured the permafrost temperature in the resulting borehole. Comparison of the submarine permafrost temperature to temperatures on land reveal warming of permafrost by 8 to 10 °C over a period of less than a millennium. During this time, the top of the ice-bearing permafrost (IBPF) degraded from 0 to 28.8 m b.s.l. at the borehole site, a mean degradation rate of almost 3 cm per year. Geoelectric resistivity measurements corroborate this observation and show a decline of the IBPF with increasing distance from shore. Similar to many other Siberian locations, the deeper permafrost at the study site contained less organic carbon by orders of magnitude when compared to the overlying syngenetic ice complex deposits. The same held true for methane concentrations in the frozen permafrost. Our data suggest that these comparatively low concentrations of methane are oxidized in the sediment column upon thawing. Analyses of the sediment and pore water chemistry demonstrate that sea water is probably advected to the IBPF, which contributes to ... |
format |
Conference Object |
author |
Overduin, Paul Grigoriev, Mikhail N. Schirrmeister, Lutz Wetterich, Sebastian Nätscher, Valentin Günther, Frank Liebner, Susanne Knoblauch, Christian Hubberten, Hans-Wolfgang |
spellingShingle |
Overduin, Paul Grigoriev, Mikhail N. Schirrmeister, Lutz Wetterich, Sebastian Nätscher, Valentin Günther, Frank Liebner, Susanne Knoblauch, Christian Hubberten, Hans-Wolfgang Permafrost degradation and methane release in the central Laptev Sea |
author_facet |
Overduin, Paul Grigoriev, Mikhail N. Schirrmeister, Lutz Wetterich, Sebastian Nätscher, Valentin Günther, Frank Liebner, Susanne Knoblauch, Christian Hubberten, Hans-Wolfgang |
author_sort |
Overduin, Paul |
title |
Permafrost degradation and methane release in the central Laptev Sea |
title_short |
Permafrost degradation and methane release in the central Laptev Sea |
title_full |
Permafrost degradation and methane release in the central Laptev Sea |
title_fullStr |
Permafrost degradation and methane release in the central Laptev Sea |
title_full_unstemmed |
Permafrost degradation and methane release in the central Laptev Sea |
title_sort |
permafrost degradation and methane release in the central laptev sea |
publisher |
University of Lisbon and the University of Évora |
publishDate |
2014 |
url |
https://epic.awi.de/id/eprint/35772/ http://www.eucop4.org/ https://hdl.handle.net/10013/epic.43697 |
long_lat |
ENVELOPE(127.803,127.803,72.287,72.287) ENVELOPE(135.167,135.167,60.567,60.567) |
geographic |
Buor-Khaya Khaya Laptev Sea |
geographic_facet |
Buor-Khaya Khaya Laptev Sea |
genre |
Ice laptev Laptev Sea permafrost |
genre_facet |
Ice laptev Laptev Sea permafrost |
op_source |
EPIC34th European Conference on Permafrost, Evora, 2014-06-18-2014-06-21Evora, University of Lisbon and the University of Évora |
op_relation |
Overduin, P. orcid:0000-0001-9849-4712 , Grigoriev, M. N. , Schirrmeister, L. orcid:0000-0001-9455-0596 , Wetterich, S. orcid:0000-0001-9234-1192 , Nätscher, V. , Günther, F. orcid:0000-0001-8298-8937 , Liebner, S. , Knoblauch, C. and Hubberten, H. W. (2014) Permafrost degradation and methane release in the central Laptev Sea , 4th European Conference on Permafrost, Evora, 18 June 2014 - 21 June 2014 . hdl:10013/epic.43697 |
_version_ |
1809914070057353216 |