The effect of methane hydrate morphology and water saturation on seismic wave attenuation in sand under shallow sub-seafloor conditions
A better understanding of seismic wave attenuation in hydrate-bearing sediments is needed for the improved geophysical quantification of seafloor methane hydrates, important for climate change, geohazard and economic resource assessment. Hence, we conducted a series of small strain (<10−6), seism...
Published in: | Earth and Planetary Science Letters |
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ftnerc:oai:nora.nerc.ac.uk:502228 2023-05-15T17:11:50+02:00 The effect of methane hydrate morphology and water saturation on seismic wave attenuation in sand under shallow sub-seafloor conditions Best, Angus I. Priest, Jeffrey A. Clayton, Christopher R.I. Rees, Emily V.L. 2013-04-15 text http://nora.nerc.ac.uk/id/eprint/502228/ https://nora.nerc.ac.uk/id/eprint/502228/1/1-s2.0-S0012821X13001076-main.pdf https://doi.org/10.1016/j.epsl.2013.02.033 en eng https://nora.nerc.ac.uk/id/eprint/502228/1/1-s2.0-S0012821X13001076-main.pdf Best, Angus I. orcid:0000-0001-9558-4261 Priest, Jeffrey A.; Clayton, Christopher R.I.; Rees, Emily V.L. 2013 The effect of methane hydrate morphology and water saturation on seismic wave attenuation in sand under shallow sub-seafloor conditions. Earth and Planetary Science Letters, 368. 78-87. https://doi.org/10.1016/j.epsl.2013.02.033 <https://doi.org/10.1016/j.epsl.2013.02.033> cc_by CC-BY Publication - Article PeerReviewed 2013 ftnerc https://doi.org/10.1016/j.epsl.2013.02.033 2023-02-04T19:37:08Z A better understanding of seismic wave attenuation in hydrate-bearing sediments is needed for the improved geophysical quantification of seafloor methane hydrates, important for climate change, geohazard and economic resource assessment. Hence, we conducted a series of small strain (<10−6), seismic frequency (50–550 Hz), laboratory resonant column experiments on synthetic methane hydrate-bearing sands under excess-water seafloor conditions. The results show a complex dependence of P- and S-wave attenuation on hydrate saturation and morphology. P- and S-wave attenuation in excess-water hydrate-bearing sand is much higher than in excess-gas hydrate-bearing sand and increases with hydrate saturation between 0 and 0.44 (the experimental range). Theoretical modelling suggests that load-bearing hydrate is an important cause of heightened attenuation for both P- and S-waves in gas and water saturated sands, while pore-filling hydrate also contributes significantly to P-wave attenuation in water saturated sands. A squirt flow attenuation mechanism, related to microporous hydrate and low aspect ratio pores at the interface between sand grains and hydrate, is thought to be responsible for the heightened levels of attenuation in hydrate-bearing sands at low hydrate saturations (<0.44). Article in Journal/Newspaper Methane hydrate Natural Environment Research Council: NERC Open Research Archive Earth and Planetary Science Letters 368 78 87 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
A better understanding of seismic wave attenuation in hydrate-bearing sediments is needed for the improved geophysical quantification of seafloor methane hydrates, important for climate change, geohazard and economic resource assessment. Hence, we conducted a series of small strain (<10−6), seismic frequency (50–550 Hz), laboratory resonant column experiments on synthetic methane hydrate-bearing sands under excess-water seafloor conditions. The results show a complex dependence of P- and S-wave attenuation on hydrate saturation and morphology. P- and S-wave attenuation in excess-water hydrate-bearing sand is much higher than in excess-gas hydrate-bearing sand and increases with hydrate saturation between 0 and 0.44 (the experimental range). Theoretical modelling suggests that load-bearing hydrate is an important cause of heightened attenuation for both P- and S-waves in gas and water saturated sands, while pore-filling hydrate also contributes significantly to P-wave attenuation in water saturated sands. A squirt flow attenuation mechanism, related to microporous hydrate and low aspect ratio pores at the interface between sand grains and hydrate, is thought to be responsible for the heightened levels of attenuation in hydrate-bearing sands at low hydrate saturations (<0.44). |
format |
Article in Journal/Newspaper |
author |
Best, Angus I. Priest, Jeffrey A. Clayton, Christopher R.I. Rees, Emily V.L. |
spellingShingle |
Best, Angus I. Priest, Jeffrey A. Clayton, Christopher R.I. Rees, Emily V.L. The effect of methane hydrate morphology and water saturation on seismic wave attenuation in sand under shallow sub-seafloor conditions |
author_facet |
Best, Angus I. Priest, Jeffrey A. Clayton, Christopher R.I. Rees, Emily V.L. |
author_sort |
Best, Angus I. |
title |
The effect of methane hydrate morphology and water saturation on seismic wave attenuation in sand under shallow sub-seafloor conditions |
title_short |
The effect of methane hydrate morphology and water saturation on seismic wave attenuation in sand under shallow sub-seafloor conditions |
title_full |
The effect of methane hydrate morphology and water saturation on seismic wave attenuation in sand under shallow sub-seafloor conditions |
title_fullStr |
The effect of methane hydrate morphology and water saturation on seismic wave attenuation in sand under shallow sub-seafloor conditions |
title_full_unstemmed |
The effect of methane hydrate morphology and water saturation on seismic wave attenuation in sand under shallow sub-seafloor conditions |
title_sort |
effect of methane hydrate morphology and water saturation on seismic wave attenuation in sand under shallow sub-seafloor conditions |
publishDate |
2013 |
url |
http://nora.nerc.ac.uk/id/eprint/502228/ https://nora.nerc.ac.uk/id/eprint/502228/1/1-s2.0-S0012821X13001076-main.pdf https://doi.org/10.1016/j.epsl.2013.02.033 |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_relation |
https://nora.nerc.ac.uk/id/eprint/502228/1/1-s2.0-S0012821X13001076-main.pdf Best, Angus I. orcid:0000-0001-9558-4261 Priest, Jeffrey A.; Clayton, Christopher R.I.; Rees, Emily V.L. 2013 The effect of methane hydrate morphology and water saturation on seismic wave attenuation in sand under shallow sub-seafloor conditions. Earth and Planetary Science Letters, 368. 78-87. https://doi.org/10.1016/j.epsl.2013.02.033 <https://doi.org/10.1016/j.epsl.2013.02.033> |
op_rights |
cc_by |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1016/j.epsl.2013.02.033 |
container_title |
Earth and Planetary Science Letters |
container_volume |
368 |
container_start_page |
78 |
op_container_end_page |
87 |
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1766068588065587200 |