Thermokarst primes subsea permafrost degradation and coastal change
Subsea permafrost forms when sea level rise from deglaciation or coastal erosion results in inundation of terrestrial permafrost. The response of permafrost to flooding in these settings will be determined by both ice-rich Pleistocene deposits and the thermokarst basins that thawed out during the Ho...
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Online Access: | https://epic.awi.de/id/eprint/53793/ https://agu.confex.com/agu/fm20/meetingapp.cgi/Paper/732165 https://hdl.handle.net/10013/epic.0164bc98-adee-4293-953e-7d592618083c |
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ftawi:oai:epic.awi.de:53793 2024-09-15T18:11:24+00:00 Thermokarst primes subsea permafrost degradation and coastal change Angelopoulos, Michael Overduin, Pier Paul Jenrich, Maren Nitze, Ingmar Günther, Frank Strauss, Jens Krautblatter, Michael Grigoriev, Mikhail Grosse, Guido 2020-12-07 https://epic.awi.de/id/eprint/53793/ https://agu.confex.com/agu/fm20/meetingapp.cgi/Paper/732165 https://hdl.handle.net/10013/epic.0164bc98-adee-4293-953e-7d592618083c unknown AGU Angelopoulos, M. orcid:0000-0003-2574-5108 , Overduin, P. P. orcid:0000-0001-9849-4712 , Jenrich, M. orcid:0000-0002-1330-7461 , Nitze, I. orcid:0000-0002-1165-6852 , Günther, F. orcid:0000-0001-8298-8937 , Strauss, J. orcid:0000-0003-4678-4982 , Krautblatter, M. , Grigoriev, M. and Grosse, G. orcid:0000-0001-5895-2141 (2020) Thermokarst primes subsea permafrost degradation and coastal change , AGU Fall Meeting 2020, Virtual/Online, 1 December 2020 - 17 December 2020 . hdl:10013/epic.0164bc98-adee-4293-953e-7d592618083c EPIC3AGU Fall Meeting 2020, Virtual/Online, 2020-12-01-2020-12-17AGU Conference notRev 2020 ftawi 2024-06-24T04:26:11Z Subsea permafrost forms when sea level rise from deglaciation or coastal erosion results in inundation of terrestrial permafrost. The response of permafrost to flooding in these settings will be determined by both ice-rich Pleistocene deposits and the thermokarst basins that thawed out during the Holocene. Thermokarst processes lower ground ice content, create partially drained and refrozen depressions (Alases) and thaw bulbs (taliks) beneath them, warm the ground, and can thaw the ground below sea level. We hypothesize that inundated Alases offshore with relatively lower ice content and higher porewater salinities in their sediments (possibly resulting from lagoon interaction) thaw faster than Yedoma terrain. To test this hypothesis, we estimated permafrost thaw rates offshore of the Bykovsky Peninsula in Tiksi Bay, northeastern Siberia using geoelectric surveys with floating electrodes. The surveys traversed a former undrained lagoon, drained and refrozen Alas deposits, and undisturbed Yedoma terrain at varying distances from shore. A continuous Yedoma-Alas-beach-lagoon survey was also carried out to obtain an indication of pre-inundation subsurface electrical resistivity. While the estimated degradation rates of the submerged Yedoma lies in the range of similar sites, and slows with increasing distance offshore, the Alas rates were more diverse and at least twice as fast within 125 m of the coastline. The latter is possibly due to saline lagoon water that infiltrated the Alas while it was still unfrozen. The ice-bearing permafrost depths of the former lagoon were generally the deepest of the terrain units, but displayed poor correlation with distance offshore. We attribute this to heterogeneous talik thickness upon the lagoon to sea transition, as well as permafrost aggradation processes beneath the spit. Given the prevalence of thermokarst basins and lakes along parts of the Arctic coastline, their effect on subsea permafrost degradation must be similarly prevalent. Remote sensing analyses suggest that 40% ... Conference Object Ice permafrost Thermokarst Tiksi Tiksi Bay Siberia Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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 |
Subsea permafrost forms when sea level rise from deglaciation or coastal erosion results in inundation of terrestrial permafrost. The response of permafrost to flooding in these settings will be determined by both ice-rich Pleistocene deposits and the thermokarst basins that thawed out during the Holocene. Thermokarst processes lower ground ice content, create partially drained and refrozen depressions (Alases) and thaw bulbs (taliks) beneath them, warm the ground, and can thaw the ground below sea level. We hypothesize that inundated Alases offshore with relatively lower ice content and higher porewater salinities in their sediments (possibly resulting from lagoon interaction) thaw faster than Yedoma terrain. To test this hypothesis, we estimated permafrost thaw rates offshore of the Bykovsky Peninsula in Tiksi Bay, northeastern Siberia using geoelectric surveys with floating electrodes. The surveys traversed a former undrained lagoon, drained and refrozen Alas deposits, and undisturbed Yedoma terrain at varying distances from shore. A continuous Yedoma-Alas-beach-lagoon survey was also carried out to obtain an indication of pre-inundation subsurface electrical resistivity. While the estimated degradation rates of the submerged Yedoma lies in the range of similar sites, and slows with increasing distance offshore, the Alas rates were more diverse and at least twice as fast within 125 m of the coastline. The latter is possibly due to saline lagoon water that infiltrated the Alas while it was still unfrozen. The ice-bearing permafrost depths of the former lagoon were generally the deepest of the terrain units, but displayed poor correlation with distance offshore. We attribute this to heterogeneous talik thickness upon the lagoon to sea transition, as well as permafrost aggradation processes beneath the spit. Given the prevalence of thermokarst basins and lakes along parts of the Arctic coastline, their effect on subsea permafrost degradation must be similarly prevalent. Remote sensing analyses suggest that 40% ... |
format |
Conference Object |
author |
Angelopoulos, Michael Overduin, Pier Paul Jenrich, Maren Nitze, Ingmar Günther, Frank Strauss, Jens Krautblatter, Michael Grigoriev, Mikhail Grosse, Guido |
spellingShingle |
Angelopoulos, Michael Overduin, Pier Paul Jenrich, Maren Nitze, Ingmar Günther, Frank Strauss, Jens Krautblatter, Michael Grigoriev, Mikhail Grosse, Guido Thermokarst primes subsea permafrost degradation and coastal change |
author_facet |
Angelopoulos, Michael Overduin, Pier Paul Jenrich, Maren Nitze, Ingmar Günther, Frank Strauss, Jens Krautblatter, Michael Grigoriev, Mikhail Grosse, Guido |
author_sort |
Angelopoulos, Michael |
title |
Thermokarst primes subsea permafrost degradation and coastal change |
title_short |
Thermokarst primes subsea permafrost degradation and coastal change |
title_full |
Thermokarst primes subsea permafrost degradation and coastal change |
title_fullStr |
Thermokarst primes subsea permafrost degradation and coastal change |
title_full_unstemmed |
Thermokarst primes subsea permafrost degradation and coastal change |
title_sort |
thermokarst primes subsea permafrost degradation and coastal change |
publisher |
AGU |
publishDate |
2020 |
url |
https://epic.awi.de/id/eprint/53793/ https://agu.confex.com/agu/fm20/meetingapp.cgi/Paper/732165 https://hdl.handle.net/10013/epic.0164bc98-adee-4293-953e-7d592618083c |
genre |
Ice permafrost Thermokarst Tiksi Tiksi Bay Siberia |
genre_facet |
Ice permafrost Thermokarst Tiksi Tiksi Bay Siberia |
op_source |
EPIC3AGU Fall Meeting 2020, Virtual/Online, 2020-12-01-2020-12-17AGU |
op_relation |
Angelopoulos, M. orcid:0000-0003-2574-5108 , Overduin, P. P. orcid:0000-0001-9849-4712 , Jenrich, M. orcid:0000-0002-1330-7461 , Nitze, I. orcid:0000-0002-1165-6852 , Günther, F. orcid:0000-0001-8298-8937 , Strauss, J. orcid:0000-0003-4678-4982 , Krautblatter, M. , Grigoriev, M. and Grosse, G. orcid:0000-0001-5895-2141 (2020) Thermokarst primes subsea permafrost degradation and coastal change , AGU Fall Meeting 2020, Virtual/Online, 1 December 2020 - 17 December 2020 . hdl:10013/epic.0164bc98-adee-4293-953e-7d592618083c |
_version_ |
1810448985283887104 |