Spatial changes in gas transport and sediment stiffness influenced by regional stress: Observations from piezometer data along Vestnesa Ridge, eastern Fram Strait
Gas transport through sediments to the seabed and seepage occurs via advection through pores, faults, and fractures, and as solubility driven gas diffusion. The pore pressure gradient is a key factor in these processes. Yet, in-situ measurements for quantitative studies of fluid dynamics and sedimen...
Published in: | Journal of Geophysical Research: Solid Earth |
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Language: | English |
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American Geophysical Union (AGU)
2023
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Online Access: | https://archimer.ifremer.fr/doc/00834/94639/102048.pdf https://archimer.ifremer.fr/doc/00834/94639/102136.pdf https://doi.org/10.1029/2022JB025868 https://archimer.ifremer.fr/doc/00834/94639/ |
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ftarchimer:oai:archimer.ifremer.fr:94639 2023-11-12T04:17:16+01:00 Spatial changes in gas transport and sediment stiffness influenced by regional stress: Observations from piezometer data along Vestnesa Ridge, eastern Fram Strait Plaza‐faverola, A. Sultan, Nabil Lucchi, R. G. El Bani Altuna, N. Ramachandran, H. Singhroha, S. Cooke, F. Vadakkepuliyambatta, S. Ezat, M. M. Rasmussen, T. L. 2023-05 application/pdf https://archimer.ifremer.fr/doc/00834/94639/102048.pdf https://archimer.ifremer.fr/doc/00834/94639/102136.pdf https://doi.org/10.1029/2022JB025868 https://archimer.ifremer.fr/doc/00834/94639/ eng eng American Geophysical Union (AGU) https://archimer.ifremer.fr/doc/00834/94639/102048.pdf https://archimer.ifremer.fr/doc/00834/94639/102136.pdf doi:10.1029/2022JB025868 https://archimer.ifremer.fr/doc/00834/94639/ info:eu-repo/semantics/openAccess restricted use Journal Of Geophysical Research-solid Earth (2169-9313) (American Geophysical Union (AGU)), 2023-05 , Vol. 128 , N. 5 , P. e2022JB025868 (21p.) in situ pore pressures methane transport fine-grained sediments sedimentary faulting stiffness Fram Strait text Article info:eu-repo/semantics/article 2023 ftarchimer https://doi.org/10.1029/2022JB025868 2023-10-31T23:51:09Z Gas transport through sediments to the seabed and seepage occurs via advection through pores, faults, and fractures, and as solubility driven gas diffusion. The pore pressure gradient is a key factor in these processes. Yet, in-situ measurements for quantitative studies of fluid dynamics and sediment deformation in deep ocean environments remain scarce. In this study, we integrate piezometer data, geotechnical tests, and sediment core analyses to study the pressure regime that controls gas transport along the Vestnesa Ridge in the eastern Fram Strait. The data show a progressive westward decrease in induced pore pressure (i.e., from c. 180 to c. 50 kPa) upon piezometer penetration and undrained shear strength of the sediments, interpreted as a decrease in sediment stiffness. In addition, the data suggest that the upper c. 6 m of sediments may be mechanically damaged due to variations in gas diffusion rates and exsolution. Background pore pressures are mostly at hydrostatic conditions, but localized excess pore pressures (i.e., up to 10 kPa) exist and point towards external controls. When analyzed in conjunction with observations from geophysical data and sediment core analyses, the pore pressure data suggest a spatial change from an advection dominated to a diffusion dominated fluid flow system, influenced by the behavior of sedimentary faults. Understanding gas transport mechanisms and their effect on fine-grained sediments of deep ocean settings is critical for constraining gas hydrate inventories, seepage phenomena and sub-seabed sediment deformations and instabilities. Key Points This study documents in-situ pore pressure measurements along the gas charged Vestnesa sedimentary ridge in the eastern Fram Strait. Integrated piezometer and calypso core analyses indicate spatial variations in sediment stiffness and localized excess pore pressures. Gas transport and sub-seabed sediment stiffness are interrelated and affected by sea-level changes and fault behavior. Plain Language Summary Seafloor methane seepage ... Article in Journal/Newspaper Fram Strait Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Journal of Geophysical Research: Solid Earth 128 5 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
topic |
in situ pore pressures methane transport fine-grained sediments sedimentary faulting stiffness Fram Strait |
spellingShingle |
in situ pore pressures methane transport fine-grained sediments sedimentary faulting stiffness Fram Strait Plaza‐faverola, A. Sultan, Nabil Lucchi, R. G. El Bani Altuna, N. Ramachandran, H. Singhroha, S. Cooke, F. Vadakkepuliyambatta, S. Ezat, M. M. Rasmussen, T. L. Spatial changes in gas transport and sediment stiffness influenced by regional stress: Observations from piezometer data along Vestnesa Ridge, eastern Fram Strait |
topic_facet |
in situ pore pressures methane transport fine-grained sediments sedimentary faulting stiffness Fram Strait |
description |
Gas transport through sediments to the seabed and seepage occurs via advection through pores, faults, and fractures, and as solubility driven gas diffusion. The pore pressure gradient is a key factor in these processes. Yet, in-situ measurements for quantitative studies of fluid dynamics and sediment deformation in deep ocean environments remain scarce. In this study, we integrate piezometer data, geotechnical tests, and sediment core analyses to study the pressure regime that controls gas transport along the Vestnesa Ridge in the eastern Fram Strait. The data show a progressive westward decrease in induced pore pressure (i.e., from c. 180 to c. 50 kPa) upon piezometer penetration and undrained shear strength of the sediments, interpreted as a decrease in sediment stiffness. In addition, the data suggest that the upper c. 6 m of sediments may be mechanically damaged due to variations in gas diffusion rates and exsolution. Background pore pressures are mostly at hydrostatic conditions, but localized excess pore pressures (i.e., up to 10 kPa) exist and point towards external controls. When analyzed in conjunction with observations from geophysical data and sediment core analyses, the pore pressure data suggest a spatial change from an advection dominated to a diffusion dominated fluid flow system, influenced by the behavior of sedimentary faults. Understanding gas transport mechanisms and their effect on fine-grained sediments of deep ocean settings is critical for constraining gas hydrate inventories, seepage phenomena and sub-seabed sediment deformations and instabilities. Key Points This study documents in-situ pore pressure measurements along the gas charged Vestnesa sedimentary ridge in the eastern Fram Strait. Integrated piezometer and calypso core analyses indicate spatial variations in sediment stiffness and localized excess pore pressures. Gas transport and sub-seabed sediment stiffness are interrelated and affected by sea-level changes and fault behavior. Plain Language Summary Seafloor methane seepage ... |
format |
Article in Journal/Newspaper |
author |
Plaza‐faverola, A. Sultan, Nabil Lucchi, R. G. El Bani Altuna, N. Ramachandran, H. Singhroha, S. Cooke, F. Vadakkepuliyambatta, S. Ezat, M. M. Rasmussen, T. L. |
author_facet |
Plaza‐faverola, A. Sultan, Nabil Lucchi, R. G. El Bani Altuna, N. Ramachandran, H. Singhroha, S. Cooke, F. Vadakkepuliyambatta, S. Ezat, M. M. Rasmussen, T. L. |
author_sort |
Plaza‐faverola, A. |
title |
Spatial changes in gas transport and sediment stiffness influenced by regional stress: Observations from piezometer data along Vestnesa Ridge, eastern Fram Strait |
title_short |
Spatial changes in gas transport and sediment stiffness influenced by regional stress: Observations from piezometer data along Vestnesa Ridge, eastern Fram Strait |
title_full |
Spatial changes in gas transport and sediment stiffness influenced by regional stress: Observations from piezometer data along Vestnesa Ridge, eastern Fram Strait |
title_fullStr |
Spatial changes in gas transport and sediment stiffness influenced by regional stress: Observations from piezometer data along Vestnesa Ridge, eastern Fram Strait |
title_full_unstemmed |
Spatial changes in gas transport and sediment stiffness influenced by regional stress: Observations from piezometer data along Vestnesa Ridge, eastern Fram Strait |
title_sort |
spatial changes in gas transport and sediment stiffness influenced by regional stress: observations from piezometer data along vestnesa ridge, eastern fram strait |
publisher |
American Geophysical Union (AGU) |
publishDate |
2023 |
url |
https://archimer.ifremer.fr/doc/00834/94639/102048.pdf https://archimer.ifremer.fr/doc/00834/94639/102136.pdf https://doi.org/10.1029/2022JB025868 https://archimer.ifremer.fr/doc/00834/94639/ |
genre |
Fram Strait |
genre_facet |
Fram Strait |
op_source |
Journal Of Geophysical Research-solid Earth (2169-9313) (American Geophysical Union (AGU)), 2023-05 , Vol. 128 , N. 5 , P. e2022JB025868 (21p.) |
op_relation |
https://archimer.ifremer.fr/doc/00834/94639/102048.pdf https://archimer.ifremer.fr/doc/00834/94639/102136.pdf doi:10.1029/2022JB025868 https://archimer.ifremer.fr/doc/00834/94639/ |
op_rights |
info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1029/2022JB025868 |
container_title |
Journal of Geophysical Research: Solid Earth |
container_volume |
128 |
container_issue |
5 |
_version_ |
1782334222384496640 |