Foldback reflectors near methane hydrate bottom‐simulating reflectors: Indicators of gas distribution from 3 D seismic images in the eastern Nankai Trough
Abstract Understanding of fluid behavior and gas distribution in the shallow subsurface are important considerations in gas hydrate formation and the global carbon cycle. Estimation of gas distribution based on reflection seismic surveys, however, is difficult because the boundary of a gas‐bearing z...
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crwiley:10.1111/iar.12099 2024-09-15T18:18:41+00:00 Foldback reflectors near methane hydrate bottom‐simulating reflectors: Indicators of gas distribution from 3 D seismic images in the eastern Nankai Trough Otsuka, Hironori Morita, Sumito Tanahashi, Manabu Ashi, Juichiro Grant-Aid for Scientific Research on innovative Areas 2015 http://dx.doi.org/10.1111/iar.12099 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fiar.12099 https://onlinelibrary.wiley.com/doi/pdf/10.1111/iar.12099 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Island Arc volume 24, issue 2, page 145-158 ISSN 1038-4871 1440-1738 journal-article 2015 crwiley https://doi.org/10.1111/iar.12099 2024-08-13T04:17:35Z Abstract Understanding of fluid behavior and gas distribution in the shallow subsurface are important considerations in gas hydrate formation and the global carbon cycle. Estimation of gas distribution based on reflection seismic surveys, however, is difficult because the boundary of a gas‐bearing zone is indistinct and not systematically defined. This study reports distinctive features related to gas‐hydrate distribution and possible fluid migration in high‐resolution 3 D seismic‐reflection data from sediments of the eastern N ankai T rough. These features, here termed foldback reflectors ( FBRs ), descend in accordion shaped reflectors near the edges of bottom‐simulating reflectors ( BSRs ). FBRs generally correspond to lateral boundaries between two seismic facies, a ‘dimmed’ facies with relatively low amplitude and subdued high‐frequency components beneath the BSR and the contrasting facies around the BSR . The dimmed facies corresponds to areas of anomalously low velocity consistent with a small amount of free gas. FBR is mostly developed in well‐stratified formations in uplifted regions. Dip directions of the FBR appear to be restricted by orientation of the host formations. Edges of the FBR often correspond to high‐amplitude layers. Such occurrences of FBR suggest that regional uplift and layer‐parallel fluid migration are related to the formation of FBR as well as BSR . Article in Journal/Newspaper Methane hydrate Wiley Online Library Island Arc 24 2 145 158 |
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Wiley Online Library |
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English |
description |
Abstract Understanding of fluid behavior and gas distribution in the shallow subsurface are important considerations in gas hydrate formation and the global carbon cycle. Estimation of gas distribution based on reflection seismic surveys, however, is difficult because the boundary of a gas‐bearing zone is indistinct and not systematically defined. This study reports distinctive features related to gas‐hydrate distribution and possible fluid migration in high‐resolution 3 D seismic‐reflection data from sediments of the eastern N ankai T rough. These features, here termed foldback reflectors ( FBRs ), descend in accordion shaped reflectors near the edges of bottom‐simulating reflectors ( BSRs ). FBRs generally correspond to lateral boundaries between two seismic facies, a ‘dimmed’ facies with relatively low amplitude and subdued high‐frequency components beneath the BSR and the contrasting facies around the BSR . The dimmed facies corresponds to areas of anomalously low velocity consistent with a small amount of free gas. FBR is mostly developed in well‐stratified formations in uplifted regions. Dip directions of the FBR appear to be restricted by orientation of the host formations. Edges of the FBR often correspond to high‐amplitude layers. Such occurrences of FBR suggest that regional uplift and layer‐parallel fluid migration are related to the formation of FBR as well as BSR . |
author2 |
Grant-Aid for Scientific Research on innovative Areas |
format |
Article in Journal/Newspaper |
author |
Otsuka, Hironori Morita, Sumito Tanahashi, Manabu Ashi, Juichiro |
spellingShingle |
Otsuka, Hironori Morita, Sumito Tanahashi, Manabu Ashi, Juichiro Foldback reflectors near methane hydrate bottom‐simulating reflectors: Indicators of gas distribution from 3 D seismic images in the eastern Nankai Trough |
author_facet |
Otsuka, Hironori Morita, Sumito Tanahashi, Manabu Ashi, Juichiro |
author_sort |
Otsuka, Hironori |
title |
Foldback reflectors near methane hydrate bottom‐simulating reflectors: Indicators of gas distribution from 3 D seismic images in the eastern Nankai Trough |
title_short |
Foldback reflectors near methane hydrate bottom‐simulating reflectors: Indicators of gas distribution from 3 D seismic images in the eastern Nankai Trough |
title_full |
Foldback reflectors near methane hydrate bottom‐simulating reflectors: Indicators of gas distribution from 3 D seismic images in the eastern Nankai Trough |
title_fullStr |
Foldback reflectors near methane hydrate bottom‐simulating reflectors: Indicators of gas distribution from 3 D seismic images in the eastern Nankai Trough |
title_full_unstemmed |
Foldback reflectors near methane hydrate bottom‐simulating reflectors: Indicators of gas distribution from 3 D seismic images in the eastern Nankai Trough |
title_sort |
foldback reflectors near methane hydrate bottom‐simulating reflectors: indicators of gas distribution from 3 d seismic images in the eastern nankai trough |
publisher |
Wiley |
publishDate |
2015 |
url |
http://dx.doi.org/10.1111/iar.12099 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fiar.12099 https://onlinelibrary.wiley.com/doi/pdf/10.1111/iar.12099 |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_source |
Island Arc volume 24, issue 2, page 145-158 ISSN 1038-4871 1440-1738 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/iar.12099 |
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Island Arc |
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24 |
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2 |
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145 |
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158 |
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1810456771404234752 |