Multiple failure styles related to shallow gas and fluid venting, upper slope Canadian Beaufort Sea, northern Canada
The continental slope of the Canadian Beaufort Sea presents an exceptional opportunity to study the relationship between the fluid venting and the formation of mass-transport deposits. The continental shelf was emergent and partially ice-free during the last glaciation and is underlain by widespread...
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Online Access: | https://scholars.unh.edu/ccom/1314 https://doi.org/10.1016/j.margeo.2014.05.014 |
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ftuninhampshire:oai:scholars.unh.edu:ccom-2313 2023-05-15T15:15:10+02:00 Multiple failure styles related to shallow gas and fluid venting, upper slope Canadian Beaufort Sea, northern Canada Saint-Ange, Francky Kuus, Pim Blasco, Steve Piper, David J.W. Hughes Clarke, John E. MacKillop, Kevin 2014-09-01T07:00:00Z https://scholars.unh.edu/ccom/1314 https://doi.org/10.1016/j.margeo.2014.05.014 unknown University of New Hampshire Scholars' Repository https://scholars.unh.edu/ccom/1314 https://doi.org/10.1016/j.margeo.2014.05.014 Center for Coastal and Ocean Mapping gas seeps creep slope failure permafrost multibeam water column backscatter Arctic text 2014 ftuninhampshire https://doi.org/10.1016/j.margeo.2014.05.014 2023-01-30T21:47:55Z The continental slope of the Canadian Beaufort Sea presents an exceptional opportunity to study the relationship between the fluid venting and the formation of mass-transport deposits. The continental shelf was emergent and partially ice-free during the last glaciation and is underlain by widespread permafrost. Water-column backscatter has shown the locations of more than 40 active gas vents along seaward margin of the subsea permafrost at the shelf break and upper slope. New multibeam bathymetry and subbottom profiler data show shallow potentially late Holocene failures and mass-transport deposits on the upper slope. Upslope from a prominent headscarp, undulating seabed with apparent growth faults overlies an acoustically incoherent to stratified horizon at 50 m sub-bottom interpreted as a decollement surface over which progressive creep has occurred. Similar creep is present in places on the upper slope and in places seems to have evolved into small translational slides, involving more compacted sediment buried > 25 m, or into muddy debris flows where sediments buried < 25 m have failed. Much of the slope failed during a regional retrogressive event, the Ikit slump, likely initiated on steep channel walls on the lower slope. Characteristic ridge and trough morphology resulting from retrogressive spreading or rotational slumping are preserved on gradients < 2° on the upper slope, but appear to have been completely evacuated on gradients of 3° on the mid slope, where muddy debris-flow deposits are found. Correlations between radiocarbon dated cores and sub-bottom profiles show that the retrogressive failure occurred in the last 1000 years. This study implies that Holocene shelf break and upper slope stability in the Beaufort Sea are strongly linked to the dynamics of the permafrost and the presence of weak, gas-rich sediments. It demonstrates that creep deformation evolves into either muddy debris flows or translational slides, dependent on sediment strength. Text Arctic Beaufort Sea Ice permafrost University of New Hampshire: Scholars Repository Arctic Canada Marine Geology 355 136 149 |
institution |
Open Polar |
collection |
University of New Hampshire: Scholars Repository |
op_collection_id |
ftuninhampshire |
language |
unknown |
topic |
gas seeps creep slope failure permafrost multibeam water column backscatter Arctic |
spellingShingle |
gas seeps creep slope failure permafrost multibeam water column backscatter Arctic Saint-Ange, Francky Kuus, Pim Blasco, Steve Piper, David J.W. Hughes Clarke, John E. MacKillop, Kevin Multiple failure styles related to shallow gas and fluid venting, upper slope Canadian Beaufort Sea, northern Canada |
topic_facet |
gas seeps creep slope failure permafrost multibeam water column backscatter Arctic |
description |
The continental slope of the Canadian Beaufort Sea presents an exceptional opportunity to study the relationship between the fluid venting and the formation of mass-transport deposits. The continental shelf was emergent and partially ice-free during the last glaciation and is underlain by widespread permafrost. Water-column backscatter has shown the locations of more than 40 active gas vents along seaward margin of the subsea permafrost at the shelf break and upper slope. New multibeam bathymetry and subbottom profiler data show shallow potentially late Holocene failures and mass-transport deposits on the upper slope. Upslope from a prominent headscarp, undulating seabed with apparent growth faults overlies an acoustically incoherent to stratified horizon at 50 m sub-bottom interpreted as a decollement surface over which progressive creep has occurred. Similar creep is present in places on the upper slope and in places seems to have evolved into small translational slides, involving more compacted sediment buried > 25 m, or into muddy debris flows where sediments buried < 25 m have failed. Much of the slope failed during a regional retrogressive event, the Ikit slump, likely initiated on steep channel walls on the lower slope. Characteristic ridge and trough morphology resulting from retrogressive spreading or rotational slumping are preserved on gradients < 2° on the upper slope, but appear to have been completely evacuated on gradients of 3° on the mid slope, where muddy debris-flow deposits are found. Correlations between radiocarbon dated cores and sub-bottom profiles show that the retrogressive failure occurred in the last 1000 years. This study implies that Holocene shelf break and upper slope stability in the Beaufort Sea are strongly linked to the dynamics of the permafrost and the presence of weak, gas-rich sediments. It demonstrates that creep deformation evolves into either muddy debris flows or translational slides, dependent on sediment strength. |
format |
Text |
author |
Saint-Ange, Francky Kuus, Pim Blasco, Steve Piper, David J.W. Hughes Clarke, John E. MacKillop, Kevin |
author_facet |
Saint-Ange, Francky Kuus, Pim Blasco, Steve Piper, David J.W. Hughes Clarke, John E. MacKillop, Kevin |
author_sort |
Saint-Ange, Francky |
title |
Multiple failure styles related to shallow gas and fluid venting, upper slope Canadian Beaufort Sea, northern Canada |
title_short |
Multiple failure styles related to shallow gas and fluid venting, upper slope Canadian Beaufort Sea, northern Canada |
title_full |
Multiple failure styles related to shallow gas and fluid venting, upper slope Canadian Beaufort Sea, northern Canada |
title_fullStr |
Multiple failure styles related to shallow gas and fluid venting, upper slope Canadian Beaufort Sea, northern Canada |
title_full_unstemmed |
Multiple failure styles related to shallow gas and fluid venting, upper slope Canadian Beaufort Sea, northern Canada |
title_sort |
multiple failure styles related to shallow gas and fluid venting, upper slope canadian beaufort sea, northern canada |
publisher |
University of New Hampshire Scholars' Repository |
publishDate |
2014 |
url |
https://scholars.unh.edu/ccom/1314 https://doi.org/10.1016/j.margeo.2014.05.014 |
geographic |
Arctic Canada |
geographic_facet |
Arctic Canada |
genre |
Arctic Beaufort Sea Ice permafrost |
genre_facet |
Arctic Beaufort Sea Ice permafrost |
op_source |
Center for Coastal and Ocean Mapping |
op_relation |
https://scholars.unh.edu/ccom/1314 https://doi.org/10.1016/j.margeo.2014.05.014 |
op_doi |
https://doi.org/10.1016/j.margeo.2014.05.014 |
container_title |
Marine Geology |
container_volume |
355 |
container_start_page |
136 |
op_container_end_page |
149 |
_version_ |
1766345550686322688 |