In situ measurements of thermal diffusivity in sediments of the methane-rich zone of Cascadia Margin, NE Pacific Ocean
Abstract Thermal diffusivity (TD) is a measure of the temperature response of a material to external thermal forcing. In this study, TD values for marine sediments were determined in situ at two locations on the Cascadia Margin using an instrumented sediment probe deployed by a remotely operated veh...
Published in: | Elementa: Science of the Anthropocene |
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ftdoajarticles:oai:doaj.org/article:44308c96605a4a43ba3b8b069f5e4d10 2023-05-15T17:11:54+02:00 In situ measurements of thermal diffusivity in sediments of the methane-rich zone of Cascadia Margin, NE Pacific Ocean Kira Homola H. Paul Johnson Casey Hearn 2015-02-01T00:00:00Z https://doi.org/10.12952/journal.elementa.000039 https://doaj.org/article/44308c96605a4a43ba3b8b069f5e4d10 EN eng BioOne http://elementascience.org/article/info:doi/10.12952/journal.elementa.000039 https://doaj.org/toc/2325-1026 2325-1026 doi:10.12952/journal.elementa.000039 https://doaj.org/article/44308c96605a4a43ba3b8b069f5e4d10 Elementa: Science of the Anthropocene (2015) thermal diffusivity marine sediments Cascadia Margin Environmental sciences GE1-350 article 2015 ftdoajarticles https://doi.org/10.12952/journal.elementa.000039 2022-12-31T12:27:57Z Abstract Thermal diffusivity (TD) is a measure of the temperature response of a material to external thermal forcing. In this study, TD values for marine sediments were determined in situ at two locations on the Cascadia Margin using an instrumented sediment probe deployed by a remotely operated vehicle. TD measurements in this area of the NE Pacific Ocean are important for characterizing the upslope edge of the methane hydrate stability zone, which is the climate-sensitive boundary of a global-scale carbon reservoir. The probe was deployed on the Cascadia Margin at water depths of 552 and 1049 m for a total of 6 days at each site. The instrumented probe consisted of four thermistors aligned vertically, one sensor exposed to the bottom water and one each at 5, 10, and 15 cm within the sediment. Results from each deployment were analyzed using a thermal conduction model applying a range of TD values to obtain the best fit with the experimental data. TD values corresponding to the lowest standard deviations from the numerical model runs were selected as the best approximations. Overall TDs of Cascadia Margin sediments of 4.33 and 1.15 × 10–7 m2 s–1 were calculated for the two deployments. These values, the first of their kind to be determined from in situ measurements on a methane hydrate-rich continental margin, are expected to be useful in the development of models of bottom-water temperature increases and their implications on a global scale. Article in Journal/Newspaper Methane hydrate Directory of Open Access Journals: DOAJ Articles Pacific Elementa: Science of the Anthropocene 3 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
thermal diffusivity marine sediments Cascadia Margin Environmental sciences GE1-350 |
spellingShingle |
thermal diffusivity marine sediments Cascadia Margin Environmental sciences GE1-350 Kira Homola H. Paul Johnson Casey Hearn In situ measurements of thermal diffusivity in sediments of the methane-rich zone of Cascadia Margin, NE Pacific Ocean |
topic_facet |
thermal diffusivity marine sediments Cascadia Margin Environmental sciences GE1-350 |
description |
Abstract Thermal diffusivity (TD) is a measure of the temperature response of a material to external thermal forcing. In this study, TD values for marine sediments were determined in situ at two locations on the Cascadia Margin using an instrumented sediment probe deployed by a remotely operated vehicle. TD measurements in this area of the NE Pacific Ocean are important for characterizing the upslope edge of the methane hydrate stability zone, which is the climate-sensitive boundary of a global-scale carbon reservoir. The probe was deployed on the Cascadia Margin at water depths of 552 and 1049 m for a total of 6 days at each site. The instrumented probe consisted of four thermistors aligned vertically, one sensor exposed to the bottom water and one each at 5, 10, and 15 cm within the sediment. Results from each deployment were analyzed using a thermal conduction model applying a range of TD values to obtain the best fit with the experimental data. TD values corresponding to the lowest standard deviations from the numerical model runs were selected as the best approximations. Overall TDs of Cascadia Margin sediments of 4.33 and 1.15 × 10–7 m2 s–1 were calculated for the two deployments. These values, the first of their kind to be determined from in situ measurements on a methane hydrate-rich continental margin, are expected to be useful in the development of models of bottom-water temperature increases and their implications on a global scale. |
format |
Article in Journal/Newspaper |
author |
Kira Homola H. Paul Johnson Casey Hearn |
author_facet |
Kira Homola H. Paul Johnson Casey Hearn |
author_sort |
Kira Homola |
title |
In situ measurements of thermal diffusivity in sediments of the methane-rich zone of Cascadia Margin, NE Pacific Ocean |
title_short |
In situ measurements of thermal diffusivity in sediments of the methane-rich zone of Cascadia Margin, NE Pacific Ocean |
title_full |
In situ measurements of thermal diffusivity in sediments of the methane-rich zone of Cascadia Margin, NE Pacific Ocean |
title_fullStr |
In situ measurements of thermal diffusivity in sediments of the methane-rich zone of Cascadia Margin, NE Pacific Ocean |
title_full_unstemmed |
In situ measurements of thermal diffusivity in sediments of the methane-rich zone of Cascadia Margin, NE Pacific Ocean |
title_sort |
in situ measurements of thermal diffusivity in sediments of the methane-rich zone of cascadia margin, ne pacific ocean |
publisher |
BioOne |
publishDate |
2015 |
url |
https://doi.org/10.12952/journal.elementa.000039 https://doaj.org/article/44308c96605a4a43ba3b8b069f5e4d10 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_source |
Elementa: Science of the Anthropocene (2015) |
op_relation |
http://elementascience.org/article/info:doi/10.12952/journal.elementa.000039 https://doaj.org/toc/2325-1026 2325-1026 doi:10.12952/journal.elementa.000039 https://doaj.org/article/44308c96605a4a43ba3b8b069f5e4d10 |
op_doi |
https://doi.org/10.12952/journal.elementa.000039 |
container_title |
Elementa: Science of the Anthropocene |
container_volume |
3 |
_version_ |
1766068648133263360 |