Widespread gas hydrate instability on the upper U.S. Beaufort margin
Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Solid Earth 119 (2014): 8594–8609, doi:10.1002/2014JB011290....
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/7171 2023-05-15T15:15:47+02:00 Widespread gas hydrate instability on the upper U.S. Beaufort margin Phrampus, Benjamin J. Hornbach, Matthew J. Ruppel, Carolyn D. Hart, Patrick E. 2014-12-09 application/msword application/vnd.ms-excel application/pdf https://hdl.handle.net/1912/7171 en_US eng John Wiley & Sons https://doi.org/10.1002/2014JB011290 Journal of Geophysical Research: Solid Earth 119 (2014): 8594–8609 https://hdl.handle.net/1912/7171 doi:10.1002/2014JB011290 Journal of Geophysical Research: Solid Earth 119 (2014): 8594–8609 doi:10.1002/2014JB011290 Gas hydrate Heat flow Seismic reflection Ocean temperature Modeling Beaufort Sea Article 2014 ftwhoas https://doi.org/10.1002/2014JB011290 2022-05-28T22:59:16Z Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Solid Earth 119 (2014): 8594–8609, doi:10.1002/2014JB011290. The most climate-sensitive methane hydrate deposits occur on upper continental slopes at depths close to the minimum pressure and maximum temperature for gas hydrate stability. At these water depths, small perturbations in intermediate ocean water temperatures can lead to gas hydrate dissociation. The Arctic Ocean has experienced more dramatic warming than lower latitudes, but observational data have not been used to study the interplay between upper slope gas hydrates and warming ocean waters. Here we use (a) legacy seismic data that constrain upper slope gas hydrate distributions on the U.S. Beaufort Sea margin, (b) Alaskan North Slope borehole data and offshore thermal gradients determined from gas hydrate stability zone thickness to infer regional heat flow, and (c) 1088 direct measurements to characterize multidecadal intermediate ocean warming in the U.S. Beaufort Sea. Combining these data with a three-dimensional thermal model shows that the observed gas hydrate stability zone is too deep by 100 to 250 m. The disparity can be partially attributed to several processes, but the most important is the reequilibration (thinning) of gas hydrates in response to significant (~0.5°C at 2σ certainty) warming of intermediate ocean temperatures over 39 years in a depth range that brackets the upper slope extent of the gas hydrate stability zone. Even in the absence of additional ocean warming, 0.44 to 2.2 Gt of methane could be released from reequilibrating gas hydrates into the sediments underlying an area of ~5–7.5 × 103 km2 on the U.S. Beaufort Sea upper slope during the next century. This work was supported by the U.S. Department of Energy (DOE), grant DE-FE0010180 to SMU and a USGS-DOE interagency agreement ... Article in Journal/Newspaper Arctic Arctic Ocean Beaufort Sea Methane hydrate Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Arctic Arctic Ocean Journal of Geophysical Research: Solid Earth 119 12 8594 8609 |
institution |
Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Gas hydrate Heat flow Seismic reflection Ocean temperature Modeling Beaufort Sea |
spellingShingle |
Gas hydrate Heat flow Seismic reflection Ocean temperature Modeling Beaufort Sea Phrampus, Benjamin J. Hornbach, Matthew J. Ruppel, Carolyn D. Hart, Patrick E. Widespread gas hydrate instability on the upper U.S. Beaufort margin |
topic_facet |
Gas hydrate Heat flow Seismic reflection Ocean temperature Modeling Beaufort Sea |
description |
Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Solid Earth 119 (2014): 8594–8609, doi:10.1002/2014JB011290. The most climate-sensitive methane hydrate deposits occur on upper continental slopes at depths close to the minimum pressure and maximum temperature for gas hydrate stability. At these water depths, small perturbations in intermediate ocean water temperatures can lead to gas hydrate dissociation. The Arctic Ocean has experienced more dramatic warming than lower latitudes, but observational data have not been used to study the interplay between upper slope gas hydrates and warming ocean waters. Here we use (a) legacy seismic data that constrain upper slope gas hydrate distributions on the U.S. Beaufort Sea margin, (b) Alaskan North Slope borehole data and offshore thermal gradients determined from gas hydrate stability zone thickness to infer regional heat flow, and (c) 1088 direct measurements to characterize multidecadal intermediate ocean warming in the U.S. Beaufort Sea. Combining these data with a three-dimensional thermal model shows that the observed gas hydrate stability zone is too deep by 100 to 250 m. The disparity can be partially attributed to several processes, but the most important is the reequilibration (thinning) of gas hydrates in response to significant (~0.5°C at 2σ certainty) warming of intermediate ocean temperatures over 39 years in a depth range that brackets the upper slope extent of the gas hydrate stability zone. Even in the absence of additional ocean warming, 0.44 to 2.2 Gt of methane could be released from reequilibrating gas hydrates into the sediments underlying an area of ~5–7.5 × 103 km2 on the U.S. Beaufort Sea upper slope during the next century. This work was supported by the U.S. Department of Energy (DOE), grant DE-FE0010180 to SMU and a USGS-DOE interagency agreement ... |
format |
Article in Journal/Newspaper |
author |
Phrampus, Benjamin J. Hornbach, Matthew J. Ruppel, Carolyn D. Hart, Patrick E. |
author_facet |
Phrampus, Benjamin J. Hornbach, Matthew J. Ruppel, Carolyn D. Hart, Patrick E. |
author_sort |
Phrampus, Benjamin J. |
title |
Widespread gas hydrate instability on the upper U.S. Beaufort margin |
title_short |
Widespread gas hydrate instability on the upper U.S. Beaufort margin |
title_full |
Widespread gas hydrate instability on the upper U.S. Beaufort margin |
title_fullStr |
Widespread gas hydrate instability on the upper U.S. Beaufort margin |
title_full_unstemmed |
Widespread gas hydrate instability on the upper U.S. Beaufort margin |
title_sort |
widespread gas hydrate instability on the upper u.s. beaufort margin |
publisher |
John Wiley & Sons |
publishDate |
2014 |
url |
https://hdl.handle.net/1912/7171 |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean Beaufort Sea Methane hydrate |
genre_facet |
Arctic Arctic Ocean Beaufort Sea Methane hydrate |
op_source |
Journal of Geophysical Research: Solid Earth 119 (2014): 8594–8609 doi:10.1002/2014JB011290 |
op_relation |
https://doi.org/10.1002/2014JB011290 Journal of Geophysical Research: Solid Earth 119 (2014): 8594–8609 https://hdl.handle.net/1912/7171 doi:10.1002/2014JB011290 |
op_doi |
https://doi.org/10.1002/2014JB011290 |
container_title |
Journal of Geophysical Research: Solid Earth |
container_volume |
119 |
container_issue |
12 |
container_start_page |
8594 |
op_container_end_page |
8609 |
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1766346134315335680 |