Correlation between tectonic stress regimes and methane seepage on the western Svalbard margin
Methane seepage occurs across the western Svalbard margin at water depths ranging from < 300 m, landward from the shelf break, to > 1000 m in regions just a few kilometres from the mid-ocean ridges in the Fram Strait. The mechanisms controlling seepage remain elusive. The Vestnesa sedimentary...
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ftdoajarticles:oai:doaj.org/article:bc7ebf3285b644e297b52360ad338c15 2023-05-15T16:18:08+02:00 Correlation between tectonic stress regimes and methane seepage on the western Svalbard margin A. Plaza-Faverola M. Keiding 2019-01-01T00:00:00Z https://doi.org/10.5194/se-10-79-2019 https://doaj.org/article/bc7ebf3285b644e297b52360ad338c15 EN eng Copernicus Publications https://www.solid-earth.net/10/79/2019/se-10-79-2019.pdf https://doaj.org/toc/1869-9510 https://doaj.org/toc/1869-9529 doi:10.5194/se-10-79-2019 1869-9510 1869-9529 https://doaj.org/article/bc7ebf3285b644e297b52360ad338c15 Solid Earth, Vol 10, Pp 79-94 (2019) Geology QE1-996.5 Stratigraphy QE640-699 article 2019 ftdoajarticles https://doi.org/10.5194/se-10-79-2019 2022-12-30T20:45:36Z Methane seepage occurs across the western Svalbard margin at water depths ranging from < 300 m, landward from the shelf break, to > 1000 m in regions just a few kilometres from the mid-ocean ridges in the Fram Strait. The mechanisms controlling seepage remain elusive. The Vestnesa sedimentary ridge, located on oceanic crust at a depth of 1000–1700 m, hosts a perennial gas hydrate and associated free gas system. The restriction of the occurrence of acoustic flares to the eastern segment of the sedimentary ridge, despite the presence of pockmarks along the entire ridge, indicates a spatial variation in seepage activity. This variation coincides with a change in the faulting pattern as well as in the characteristics of the fluid flow features. Due to the position of the Vestnesa Ridge with respect to the Molloy and Knipovich mid-ocean ridges, it has been suggested that seepage along the ridge has a tectonic control. We modelled the tectonic stress regime due to oblique spreading along the Molloy and Knipovich ridges to investigate whether spatial variations in the tectonic regime along the Vestnesa Ridge are plausible. The model predicts a zone of tensile stress that extends northward from the Knipovich Ridge and encompasses the zone of acoustic flares on the eastern Vestnesa Ridge. In this zone the orientation of the maximum principal stress is parallel to pre-existing faults. The model predicts a strike-slip stress regime in regions with pockmarks where acoustic flares have not been documented. If a certain degree of coupling is assumed between deep crustal and near-surface deformation, it is possible that ridge-push forces have influenced seepage activity in the region by interacting with the pore-pressure regime at the base of the gas hydrate stability zone. More abundant seepage on the eastern Vestnesa Ridge at present may be facilitated by the dilation of faults and fractures favourably oriented with respect to the stress field. A modified state of stress in the past, due to more significant glacial ... Article in Journal/Newspaper Fram Strait Svalbard Svalbard margin Directory of Open Access Journals: DOAJ Articles Svalbard Molloy ENVELOPE(70.065,70.065,-49.360,-49.360) Knipovich Ridge ENVELOPE(7.074,7.074,75.712,75.712) Solid Earth 10 1 79 94 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geology QE1-996.5 Stratigraphy QE640-699 |
spellingShingle |
Geology QE1-996.5 Stratigraphy QE640-699 A. Plaza-Faverola M. Keiding Correlation between tectonic stress regimes and methane seepage on the western Svalbard margin |
topic_facet |
Geology QE1-996.5 Stratigraphy QE640-699 |
description |
Methane seepage occurs across the western Svalbard margin at water depths ranging from < 300 m, landward from the shelf break, to > 1000 m in regions just a few kilometres from the mid-ocean ridges in the Fram Strait. The mechanisms controlling seepage remain elusive. The Vestnesa sedimentary ridge, located on oceanic crust at a depth of 1000–1700 m, hosts a perennial gas hydrate and associated free gas system. The restriction of the occurrence of acoustic flares to the eastern segment of the sedimentary ridge, despite the presence of pockmarks along the entire ridge, indicates a spatial variation in seepage activity. This variation coincides with a change in the faulting pattern as well as in the characteristics of the fluid flow features. Due to the position of the Vestnesa Ridge with respect to the Molloy and Knipovich mid-ocean ridges, it has been suggested that seepage along the ridge has a tectonic control. We modelled the tectonic stress regime due to oblique spreading along the Molloy and Knipovich ridges to investigate whether spatial variations in the tectonic regime along the Vestnesa Ridge are plausible. The model predicts a zone of tensile stress that extends northward from the Knipovich Ridge and encompasses the zone of acoustic flares on the eastern Vestnesa Ridge. In this zone the orientation of the maximum principal stress is parallel to pre-existing faults. The model predicts a strike-slip stress regime in regions with pockmarks where acoustic flares have not been documented. If a certain degree of coupling is assumed between deep crustal and near-surface deformation, it is possible that ridge-push forces have influenced seepage activity in the region by interacting with the pore-pressure regime at the base of the gas hydrate stability zone. More abundant seepage on the eastern Vestnesa Ridge at present may be facilitated by the dilation of faults and fractures favourably oriented with respect to the stress field. A modified state of stress in the past, due to more significant glacial ... |
format |
Article in Journal/Newspaper |
author |
A. Plaza-Faverola M. Keiding |
author_facet |
A. Plaza-Faverola M. Keiding |
author_sort |
A. Plaza-Faverola |
title |
Correlation between tectonic stress regimes and methane seepage on the western Svalbard margin |
title_short |
Correlation between tectonic stress regimes and methane seepage on the western Svalbard margin |
title_full |
Correlation between tectonic stress regimes and methane seepage on the western Svalbard margin |
title_fullStr |
Correlation between tectonic stress regimes and methane seepage on the western Svalbard margin |
title_full_unstemmed |
Correlation between tectonic stress regimes and methane seepage on the western Svalbard margin |
title_sort |
correlation between tectonic stress regimes and methane seepage on the western svalbard margin |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/se-10-79-2019 https://doaj.org/article/bc7ebf3285b644e297b52360ad338c15 |
long_lat |
ENVELOPE(70.065,70.065,-49.360,-49.360) ENVELOPE(7.074,7.074,75.712,75.712) |
geographic |
Svalbard Molloy Knipovich Ridge |
geographic_facet |
Svalbard Molloy Knipovich Ridge |
genre |
Fram Strait Svalbard Svalbard margin |
genre_facet |
Fram Strait Svalbard Svalbard margin |
op_source |
Solid Earth, Vol 10, Pp 79-94 (2019) |
op_relation |
https://www.solid-earth.net/10/79/2019/se-10-79-2019.pdf https://doaj.org/toc/1869-9510 https://doaj.org/toc/1869-9529 doi:10.5194/se-10-79-2019 1869-9510 1869-9529 https://doaj.org/article/bc7ebf3285b644e297b52360ad338c15 |
op_doi |
https://doi.org/10.5194/se-10-79-2019 |
container_title |
Solid Earth |
container_volume |
10 |
container_issue |
1 |
container_start_page |
79 |
op_container_end_page |
94 |
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1766004268568936448 |