image4_Distribution of Methane Plumes on Cascadia Margin and Implications for the Landward Limit of Methane Hydrate Stability.jpeg
Nearly 3,500 methane bubble streams, clustered into more than 1,300 methane emission sites, have been identified along the US Cascadia margin, derived both from archived published data and 2011, 2016–2018 dedicated multibeam surveys using co-registered seafloor and water column data. In this study,...
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Online Access: | https://doi.org/10.3389/feart.2021.531714.s006 https://figshare.com/articles/figure/image4_Distribution_of_Methane_Plumes_on_Cascadia_Margin_and_Implications_for_the_Landward_Limit_of_Methane_Hydrate_Stability_jpeg/14292212 |
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ftfrontimediafig:oai:figshare.com:article/14292212 2023-05-15T17:11:51+02:00 image4_Distribution of Methane Plumes on Cascadia Margin and Implications for the Landward Limit of Methane Hydrate Stability.jpeg Susan G. Merle Robert W. Embley H. Paul Johnson T.-K. Lau Benjamin J. Phrampus Nicole A. Raineault Lindsay J. Gee 2021-03-24T14:55:24Z https://doi.org/10.3389/feart.2021.531714.s006 https://figshare.com/articles/figure/image4_Distribution_of_Methane_Plumes_on_Cascadia_Margin_and_Implications_for_the_Landward_Limit_of_Methane_Hydrate_Stability_jpeg/14292212 unknown doi:10.3389/feart.2021.531714.s006 https://figshare.com/articles/figure/image4_Distribution_of_Methane_Plumes_on_Cascadia_Margin_and_Implications_for_the_Landward_Limit_of_Methane_Hydrate_Stability_jpeg/14292212 CC BY 4.0 CC-BY Solid Earth Sciences Climate Science Atmospheric Sciences not elsewhere classified Exploration Geochemistry Inorganic Geochemistry Isotope Geochemistry Organic Geochemistry Geochemistry not elsewhere classified Igneous and Metamorphic Petrology Ore Deposit Petrology Palaeontology (incl. Palynology) Structural Geology Tectonics Volcanology Geology not elsewhere classified Seismology and Seismic Exploration Glaciology Hydrogeology Natural Hazards Quaternary Environments Earth Sciences not elsewhere classified Evolutionary Impacts of Climate Change methane bubble emission sites seeps Cascadia multibeam seismic reflection bubble streams Image Figure 2021 ftfrontimediafig https://doi.org/10.3389/feart.2021.531714.s006 2021-03-24T23:56:46Z Nearly 3,500 methane bubble streams, clustered into more than 1,300 methane emission sites, have been identified along the US Cascadia margin, derived both from archived published data and 2011, 2016–2018 dedicated multibeam surveys using co-registered seafloor and water column data. In this study, new multibeam sonar surveys systematically mapped nearly 40% of the US Cascadia margin, extending from the Strait of Juan de Fuca in the north to the Mendocino fracture zone in the south, and bounded East–West by the coast and the base of the accretionary prism. The frequency-depth histogram of the bubble emission sites has a dominant peak at the 500 m isobar, which extends laterally along much of the Cascadia margin off Oregon and Washington. Comparisons with published seismic data on the distribution of bottom simulating reflectors (BSR), which is the acoustic impedance boundary between methane hydrate (solid phase) and free gas phase below, correlates the bottom simulating reflectors upward termination of the feather edge of methane hydrate stability (FEMHS) zone and the newly identified bubble emission sites off Oregon and Washington. The Cascadia margin off northern California, where the BSR ends seaward of the FEMHS, has fewer sites centered on the 500 m isobaths, although data are more limited there. We propose that the peak in bubble emission sites observed near the 500 m isobath results from migration of free gas from beneath the solid phase of the BSR upslope to the FEMHS termination zone, and suggest that this boundary will be useful to monitor for a change in methane release rate potentially related to a warming ocean. Still Image Methane hydrate Frontiers: Figshare |
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Open Polar |
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Frontiers: Figshare |
op_collection_id |
ftfrontimediafig |
language |
unknown |
topic |
Solid Earth Sciences Climate Science Atmospheric Sciences not elsewhere classified Exploration Geochemistry Inorganic Geochemistry Isotope Geochemistry Organic Geochemistry Geochemistry not elsewhere classified Igneous and Metamorphic Petrology Ore Deposit Petrology Palaeontology (incl. Palynology) Structural Geology Tectonics Volcanology Geology not elsewhere classified Seismology and Seismic Exploration Glaciology Hydrogeology Natural Hazards Quaternary Environments Earth Sciences not elsewhere classified Evolutionary Impacts of Climate Change methane bubble emission sites seeps Cascadia multibeam seismic reflection bubble streams |
spellingShingle |
Solid Earth Sciences Climate Science Atmospheric Sciences not elsewhere classified Exploration Geochemistry Inorganic Geochemistry Isotope Geochemistry Organic Geochemistry Geochemistry not elsewhere classified Igneous and Metamorphic Petrology Ore Deposit Petrology Palaeontology (incl. Palynology) Structural Geology Tectonics Volcanology Geology not elsewhere classified Seismology and Seismic Exploration Glaciology Hydrogeology Natural Hazards Quaternary Environments Earth Sciences not elsewhere classified Evolutionary Impacts of Climate Change methane bubble emission sites seeps Cascadia multibeam seismic reflection bubble streams Susan G. Merle Robert W. Embley H. Paul Johnson T.-K. Lau Benjamin J. Phrampus Nicole A. Raineault Lindsay J. Gee image4_Distribution of Methane Plumes on Cascadia Margin and Implications for the Landward Limit of Methane Hydrate Stability.jpeg |
topic_facet |
Solid Earth Sciences Climate Science Atmospheric Sciences not elsewhere classified Exploration Geochemistry Inorganic Geochemistry Isotope Geochemistry Organic Geochemistry Geochemistry not elsewhere classified Igneous and Metamorphic Petrology Ore Deposit Petrology Palaeontology (incl. Palynology) Structural Geology Tectonics Volcanology Geology not elsewhere classified Seismology and Seismic Exploration Glaciology Hydrogeology Natural Hazards Quaternary Environments Earth Sciences not elsewhere classified Evolutionary Impacts of Climate Change methane bubble emission sites seeps Cascadia multibeam seismic reflection bubble streams |
description |
Nearly 3,500 methane bubble streams, clustered into more than 1,300 methane emission sites, have been identified along the US Cascadia margin, derived both from archived published data and 2011, 2016–2018 dedicated multibeam surveys using co-registered seafloor and water column data. In this study, new multibeam sonar surveys systematically mapped nearly 40% of the US Cascadia margin, extending from the Strait of Juan de Fuca in the north to the Mendocino fracture zone in the south, and bounded East–West by the coast and the base of the accretionary prism. The frequency-depth histogram of the bubble emission sites has a dominant peak at the 500 m isobar, which extends laterally along much of the Cascadia margin off Oregon and Washington. Comparisons with published seismic data on the distribution of bottom simulating reflectors (BSR), which is the acoustic impedance boundary between methane hydrate (solid phase) and free gas phase below, correlates the bottom simulating reflectors upward termination of the feather edge of methane hydrate stability (FEMHS) zone and the newly identified bubble emission sites off Oregon and Washington. The Cascadia margin off northern California, where the BSR ends seaward of the FEMHS, has fewer sites centered on the 500 m isobaths, although data are more limited there. We propose that the peak in bubble emission sites observed near the 500 m isobath results from migration of free gas from beneath the solid phase of the BSR upslope to the FEMHS termination zone, and suggest that this boundary will be useful to monitor for a change in methane release rate potentially related to a warming ocean. |
format |
Still Image |
author |
Susan G. Merle Robert W. Embley H. Paul Johnson T.-K. Lau Benjamin J. Phrampus Nicole A. Raineault Lindsay J. Gee |
author_facet |
Susan G. Merle Robert W. Embley H. Paul Johnson T.-K. Lau Benjamin J. Phrampus Nicole A. Raineault Lindsay J. Gee |
author_sort |
Susan G. Merle |
title |
image4_Distribution of Methane Plumes on Cascadia Margin and Implications for the Landward Limit of Methane Hydrate Stability.jpeg |
title_short |
image4_Distribution of Methane Plumes on Cascadia Margin and Implications for the Landward Limit of Methane Hydrate Stability.jpeg |
title_full |
image4_Distribution of Methane Plumes on Cascadia Margin and Implications for the Landward Limit of Methane Hydrate Stability.jpeg |
title_fullStr |
image4_Distribution of Methane Plumes on Cascadia Margin and Implications for the Landward Limit of Methane Hydrate Stability.jpeg |
title_full_unstemmed |
image4_Distribution of Methane Plumes on Cascadia Margin and Implications for the Landward Limit of Methane Hydrate Stability.jpeg |
title_sort |
image4_distribution of methane plumes on cascadia margin and implications for the landward limit of methane hydrate stability.jpeg |
publishDate |
2021 |
url |
https://doi.org/10.3389/feart.2021.531714.s006 https://figshare.com/articles/figure/image4_Distribution_of_Methane_Plumes_on_Cascadia_Margin_and_Implications_for_the_Landward_Limit_of_Methane_Hydrate_Stability_jpeg/14292212 |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_relation |
doi:10.3389/feart.2021.531714.s006 https://figshare.com/articles/figure/image4_Distribution_of_Methane_Plumes_on_Cascadia_Margin_and_Implications_for_the_Landward_Limit_of_Methane_Hydrate_Stability_jpeg/14292212 |
op_rights |
CC BY 4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.3389/feart.2021.531714.s006 |
_version_ |
1766068609818296320 |