Influence of rift zones and thermokarst lakes on the formation of subaqueous permafrost and the stability zone of methane hydrates of the Laptev Sea shelf in the Pleistocene
© Izdatel'stvo Nauka. All rights reserved. This paper presents results of the analysis of the influence of talik zones associated with thermokarst lakes and processes in rift zones on the dynamics of subaqueous permafrost and zones of stability of methane hydrates for conditions of the Laptev S...
Format: | Article in Journal/Newspaper |
---|---|
Language: | unknown |
Published: |
2018
|
Subjects: | |
Online Access: | https://dspace.kpfu.ru/xmlui/handle/net/149545 |
id |
ftkazanuniv:oai:dspace.kpfu.ru:net/149545 |
---|---|
record_format |
openpolar |
spelling |
ftkazanuniv:oai:dspace.kpfu.ru:net/149545 2023-05-15T15:02:07+02:00 Influence of rift zones and thermokarst lakes on the formation of subaqueous permafrost and the stability zone of methane hydrates of the Laptev Sea shelf in the Pleistocene 2018 https://dspace.kpfu.ru/xmlui/handle/net/149545 unknown Led i Sneg 2 58 231 2076-6734 https://dspace.kpfu.ru/xmlui/handle/net/149545 SCOPUS20766734-2018-58-2-SID85048946889 Arctic shelf Glacial cycles Methane hydrates Permafrost Thermokarst lakes Article 2018 ftkazanuniv 2022-01-01T09:50:57Z © Izdatel'stvo Nauka. All rights reserved. This paper presents results of the analysis of the influence of talik zones associated with thermokarst lakes and processes in rift zones on the dynamics of subaqueous permafrost and zones of stability of methane hydrates for conditions of the Laptev Sea shelf. The model of thermophysical processes in the bottom sedi- ments together with the scenario of climate change on the Arctic shelf for the last 400 thousand years (kyr) were used. Typical value of geothermal heat flux for the most part of the shelf and for the shallow shelf (with the present-day depth of =50 m) is estimated as 60 mW/m2. It is shown that with this value the dura- tion of the interglacials and the corresponding ocean transgression periods is not sufficient for the com- plete degradation of permafrost and destruction of the gas hydrates. For a deeper shelf, however, the com- plete disappearance of the stability zone of the methane hydrates is possible during the interglacial periods. In the areas of oceanic faults (rifts), higher values of the deep heat flux increase rates of degradation of the underwater permafrost rocks in the interglacial periods as compared with the condition when the heat flux is 60 mW/m2. Intensification of degradation of the subsea permafrost is manifested in areas where ther- mokarst lakes arise, but here it is associated with the temperature rise at the upper boundary of the bottom sediments. The presence of the rift zones and/or the thermokarst lakes promotes decreasing of the present- day thickness of the permafrost, and simultaneous impact of these two factors can lead to a through thaw- ing of the shelf in the interglacials (including Holocene). Article in Journal/Newspaper Arctic Climate change laptev Laptev Sea permafrost Thermokarst Kazan Federal University Digital Repository Arctic Laptev Sea Talik ENVELOPE(146.601,146.601,59.667,59.667) |
institution |
Open Polar |
collection |
Kazan Federal University Digital Repository |
op_collection_id |
ftkazanuniv |
language |
unknown |
topic |
Arctic shelf Glacial cycles Methane hydrates Permafrost Thermokarst lakes |
spellingShingle |
Arctic shelf Glacial cycles Methane hydrates Permafrost Thermokarst lakes Influence of rift zones and thermokarst lakes on the formation of subaqueous permafrost and the stability zone of methane hydrates of the Laptev Sea shelf in the Pleistocene |
topic_facet |
Arctic shelf Glacial cycles Methane hydrates Permafrost Thermokarst lakes |
description |
© Izdatel'stvo Nauka. All rights reserved. This paper presents results of the analysis of the influence of talik zones associated with thermokarst lakes and processes in rift zones on the dynamics of subaqueous permafrost and zones of stability of methane hydrates for conditions of the Laptev Sea shelf. The model of thermophysical processes in the bottom sedi- ments together with the scenario of climate change on the Arctic shelf for the last 400 thousand years (kyr) were used. Typical value of geothermal heat flux for the most part of the shelf and for the shallow shelf (with the present-day depth of =50 m) is estimated as 60 mW/m2. It is shown that with this value the dura- tion of the interglacials and the corresponding ocean transgression periods is not sufficient for the com- plete degradation of permafrost and destruction of the gas hydrates. For a deeper shelf, however, the com- plete disappearance of the stability zone of the methane hydrates is possible during the interglacial periods. In the areas of oceanic faults (rifts), higher values of the deep heat flux increase rates of degradation of the underwater permafrost rocks in the interglacial periods as compared with the condition when the heat flux is 60 mW/m2. Intensification of degradation of the subsea permafrost is manifested in areas where ther- mokarst lakes arise, but here it is associated with the temperature rise at the upper boundary of the bottom sediments. The presence of the rift zones and/or the thermokarst lakes promotes decreasing of the present- day thickness of the permafrost, and simultaneous impact of these two factors can lead to a through thaw- ing of the shelf in the interglacials (including Holocene). |
format |
Article in Journal/Newspaper |
title |
Influence of rift zones and thermokarst lakes on the formation of subaqueous permafrost and the stability zone of methane hydrates of the Laptev Sea shelf in the Pleistocene |
title_short |
Influence of rift zones and thermokarst lakes on the formation of subaqueous permafrost and the stability zone of methane hydrates of the Laptev Sea shelf in the Pleistocene |
title_full |
Influence of rift zones and thermokarst lakes on the formation of subaqueous permafrost and the stability zone of methane hydrates of the Laptev Sea shelf in the Pleistocene |
title_fullStr |
Influence of rift zones and thermokarst lakes on the formation of subaqueous permafrost and the stability zone of methane hydrates of the Laptev Sea shelf in the Pleistocene |
title_full_unstemmed |
Influence of rift zones and thermokarst lakes on the formation of subaqueous permafrost and the stability zone of methane hydrates of the Laptev Sea shelf in the Pleistocene |
title_sort |
influence of rift zones and thermokarst lakes on the formation of subaqueous permafrost and the stability zone of methane hydrates of the laptev sea shelf in the pleistocene |
publishDate |
2018 |
url |
https://dspace.kpfu.ru/xmlui/handle/net/149545 |
long_lat |
ENVELOPE(146.601,146.601,59.667,59.667) |
geographic |
Arctic Laptev Sea Talik |
geographic_facet |
Arctic Laptev Sea Talik |
genre |
Arctic Climate change laptev Laptev Sea permafrost Thermokarst |
genre_facet |
Arctic Climate change laptev Laptev Sea permafrost Thermokarst |
op_source |
SCOPUS20766734-2018-58-2-SID85048946889 |
op_relation |
Led i Sneg 2 58 231 2076-6734 https://dspace.kpfu.ru/xmlui/handle/net/149545 |
_version_ |
1766334114322972672 |