Occurrence and structural characterization of gas hydrates associated with a cold vent field, offshore Vancouver Island
Gas hydrate samples recovered from a cold vent field offshore Vancouver Island were studied in detail both by macroscopic observations and instrumental methods (powder X-ray diffraction method (PXRD), nuclear magnetic resonance (NMR), and Raman spectroscopy). It was found that gas hydrates were mass...
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AGU (American Geophysical Union)
2005
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Online Access: | https://oceanrep.geomar.de/id/eprint/30172/ https://oceanrep.geomar.de/id/eprint/30172/1/Occurrence%20and%20structural%20characterization.pdf https://doi.org/10.1029/2005JB003900 |
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ftoceanrep:oai:oceanrep.geomar.de:30172 2023-05-15T17:57:53+02:00 Occurrence and structural characterization of gas hydrates associated with a cold vent field, offshore Vancouver Island Lu, Hailong Moudrakovski, I. Riedel, Michael Spence, G. Dutrisac, R. Ripmeester, J. Wright, F. Dallimore, S. 2005 text https://oceanrep.geomar.de/id/eprint/30172/ https://oceanrep.geomar.de/id/eprint/30172/1/Occurrence%20and%20structural%20characterization.pdf https://doi.org/10.1029/2005JB003900 en eng AGU (American Geophysical Union) https://oceanrep.geomar.de/id/eprint/30172/1/Occurrence%20and%20structural%20characterization.pdf Lu, H., Moudrakovski, I., Riedel, M. , Spence, G., Dutrisac, R., Ripmeester, J., Wright, F. and Dallimore, S. (2005) Occurrence and structural characterization of gas hydrates associated with a cold vent field, offshore Vancouver Island. Journal of Geophysical Research - Solid Earth, 110 (B10). B10204. DOI 10.1029/2005JB003900 <https://doi.org/10.1029/2005JB003900>. doi:10.1029/2005JB003900 Article PeerReviewed 2005 ftoceanrep https://doi.org/10.1029/2005JB003900 2023-04-07T15:21:26Z Gas hydrate samples recovered from a cold vent field offshore Vancouver Island were studied in detail both by macroscopic observations and instrumental methods (powder X-ray diffraction method (PXRD), nuclear magnetic resonance (NMR), and Raman spectroscopy). It was found that gas hydrates were massive from 2.64 to 2.94 m below seafloor (mbsf), elongated, nodular and tabular from 4.60 to 4.81 mbsf, and vein-like from 5.48 to 5.68 mbsf, showing a trend of decreasing hydrate content with increasing depth. All samples were determined to be structure I hydrate from PXRD, NMR, and Raman spectroscopies. The hydration numbers were estimated to be 6.1 ± 0.2 on average as determined from the methane distribution over the cage sites from NMR and Raman analytical results. Estimates of conversion levels indicated that ∼78% of the water in the massive samples was hydrate, down to a low value of ∼0.4% for the pore hydrate samples. The results are compared with measurements on synthetic hydrates and samples recovered from below the permafrost on the Mallik site. Differences in methane content and lattice parameters for synthetic and natural samples are relatively minor. Additional work is needed to address the presence of minor gas components and the heterogeneity of natural hydrate samples. Article in Journal/Newspaper permafrost OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Journal of Geophysical Research 110 B10 |
institution |
Open Polar |
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OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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ftoceanrep |
language |
English |
description |
Gas hydrate samples recovered from a cold vent field offshore Vancouver Island were studied in detail both by macroscopic observations and instrumental methods (powder X-ray diffraction method (PXRD), nuclear magnetic resonance (NMR), and Raman spectroscopy). It was found that gas hydrates were massive from 2.64 to 2.94 m below seafloor (mbsf), elongated, nodular and tabular from 4.60 to 4.81 mbsf, and vein-like from 5.48 to 5.68 mbsf, showing a trend of decreasing hydrate content with increasing depth. All samples were determined to be structure I hydrate from PXRD, NMR, and Raman spectroscopies. The hydration numbers were estimated to be 6.1 ± 0.2 on average as determined from the methane distribution over the cage sites from NMR and Raman analytical results. Estimates of conversion levels indicated that ∼78% of the water in the massive samples was hydrate, down to a low value of ∼0.4% for the pore hydrate samples. The results are compared with measurements on synthetic hydrates and samples recovered from below the permafrost on the Mallik site. Differences in methane content and lattice parameters for synthetic and natural samples are relatively minor. Additional work is needed to address the presence of minor gas components and the heterogeneity of natural hydrate samples. |
format |
Article in Journal/Newspaper |
author |
Lu, Hailong Moudrakovski, I. Riedel, Michael Spence, G. Dutrisac, R. Ripmeester, J. Wright, F. Dallimore, S. |
spellingShingle |
Lu, Hailong Moudrakovski, I. Riedel, Michael Spence, G. Dutrisac, R. Ripmeester, J. Wright, F. Dallimore, S. Occurrence and structural characterization of gas hydrates associated with a cold vent field, offshore Vancouver Island |
author_facet |
Lu, Hailong Moudrakovski, I. Riedel, Michael Spence, G. Dutrisac, R. Ripmeester, J. Wright, F. Dallimore, S. |
author_sort |
Lu, Hailong |
title |
Occurrence and structural characterization of gas hydrates associated with a cold vent field, offshore Vancouver Island |
title_short |
Occurrence and structural characterization of gas hydrates associated with a cold vent field, offshore Vancouver Island |
title_full |
Occurrence and structural characterization of gas hydrates associated with a cold vent field, offshore Vancouver Island |
title_fullStr |
Occurrence and structural characterization of gas hydrates associated with a cold vent field, offshore Vancouver Island |
title_full_unstemmed |
Occurrence and structural characterization of gas hydrates associated with a cold vent field, offshore Vancouver Island |
title_sort |
occurrence and structural characterization of gas hydrates associated with a cold vent field, offshore vancouver island |
publisher |
AGU (American Geophysical Union) |
publishDate |
2005 |
url |
https://oceanrep.geomar.de/id/eprint/30172/ https://oceanrep.geomar.de/id/eprint/30172/1/Occurrence%20and%20structural%20characterization.pdf https://doi.org/10.1029/2005JB003900 |
genre |
permafrost |
genre_facet |
permafrost |
op_relation |
https://oceanrep.geomar.de/id/eprint/30172/1/Occurrence%20and%20structural%20characterization.pdf Lu, H., Moudrakovski, I., Riedel, M. , Spence, G., Dutrisac, R., Ripmeester, J., Wright, F. and Dallimore, S. (2005) Occurrence and structural characterization of gas hydrates associated with a cold vent field, offshore Vancouver Island. Journal of Geophysical Research - Solid Earth, 110 (B10). B10204. DOI 10.1029/2005JB003900 <https://doi.org/10.1029/2005JB003900>. doi:10.1029/2005JB003900 |
op_doi |
https://doi.org/10.1029/2005JB003900 |
container_title |
Journal of Geophysical Research |
container_volume |
110 |
container_issue |
B10 |
_version_ |
1766166388852916224 |