Relations between methane venting, geological structure and seismo-tectonics in the Okhotsk Sea
Methane investigations carried out in the Okhotsk Sea show that the methane flux from the earth’s interior into the water column increased during periods of seismo-tectonic activity between 1988 and 2002. In this case, methane gas hydrates found on the northeast Sakhalin slope may have decomposed du...
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ftoceanrep:oai:oceanrep.geomar.de:4157 2024-09-30T14:40:52+00:00 Relations between methane venting, geological structure and seismo-tectonics in the Okhotsk Sea Obzhirov, A. Shakirov, R. Salyuk, A. Suess, Erwin Biebow, Nicole Salomatin, A. 2004 text https://oceanrep.geomar.de/id/eprint/4157/ https://oceanrep.geomar.de/id/eprint/4157/1/Obzhirov.pdf https://doi.org/10.1007/s00367-004-0175-0 en eng Springer https://oceanrep.geomar.de/id/eprint/4157/1/Obzhirov.pdf Obzhirov, A., Shakirov, R., Salyuk, A., Suess, E., Biebow, N. and Salomatin, A. (2004) Relations between methane venting, geological structure and seismo-tectonics in the Okhotsk Sea. Geo-Marine Letters, 24 (3). pp. 135-139. DOI 10.1007/s00367-004-0175-0 <https://doi.org/10.1007/s00367-004-0175-0>. doi:10.1007/s00367-004-0175-0 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 2004 ftoceanrep https://doi.org/10.1007/s00367-004-0175-0 2024-09-04T05:04:40Z Methane investigations carried out in the Okhotsk Sea show that the methane flux from the earth’s interior into the water column increased during periods of seismo-tectonic activity between 1988 and 2002. In this case, methane gas hydrates found on the northeast Sakhalin slope may have decomposed due to a reactivation of fault zones. Methane emissions in the Okhotsk Sea generally can be divided into two forms. Firstly, methane vents from decomposing gas hydrates and/or free gas exist below gas hydrate saturated sediments via fault zones, venting into the water column with high bubble concentrations that were recorded by echosounding. These hydro-acoustic anomalies were named “flares”. Methane concentration inside these flares reached 10,000–20,000 nl/l (background methane concentrations in the Okhotsk Sea are less than 90–100 nl/l). Secondly, methane migrates as seepage into the water column from oil- and gas-bearing sedimentary source rocks on the eastern Sakhalin shelf, without showing acoustic anomalies in the water column, probably by filtration and diffusion processes. In these areas methane concentration reached 500–3,000 nl/l. In seismo-tectonically active regions, like the northwestern part of the Okhotsk Sea, many new flares were observed. Their distribution and orientation are usually controlled by fault zones (East Sakhalin Shear Zone in the Okhotsk Sea). Article in Journal/Newspaper okhotsk sea Sakhalin OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Okhotsk Geo-Marine Letters 24 3 |
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OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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ftoceanrep |
language |
English |
description |
Methane investigations carried out in the Okhotsk Sea show that the methane flux from the earth’s interior into the water column increased during periods of seismo-tectonic activity between 1988 and 2002. In this case, methane gas hydrates found on the northeast Sakhalin slope may have decomposed due to a reactivation of fault zones. Methane emissions in the Okhotsk Sea generally can be divided into two forms. Firstly, methane vents from decomposing gas hydrates and/or free gas exist below gas hydrate saturated sediments via fault zones, venting into the water column with high bubble concentrations that were recorded by echosounding. These hydro-acoustic anomalies were named “flares”. Methane concentration inside these flares reached 10,000–20,000 nl/l (background methane concentrations in the Okhotsk Sea are less than 90–100 nl/l). Secondly, methane migrates as seepage into the water column from oil- and gas-bearing sedimentary source rocks on the eastern Sakhalin shelf, without showing acoustic anomalies in the water column, probably by filtration and diffusion processes. In these areas methane concentration reached 500–3,000 nl/l. In seismo-tectonically active regions, like the northwestern part of the Okhotsk Sea, many new flares were observed. Their distribution and orientation are usually controlled by fault zones (East Sakhalin Shear Zone in the Okhotsk Sea). |
format |
Article in Journal/Newspaper |
author |
Obzhirov, A. Shakirov, R. Salyuk, A. Suess, Erwin Biebow, Nicole Salomatin, A. |
spellingShingle |
Obzhirov, A. Shakirov, R. Salyuk, A. Suess, Erwin Biebow, Nicole Salomatin, A. Relations between methane venting, geological structure and seismo-tectonics in the Okhotsk Sea |
author_facet |
Obzhirov, A. Shakirov, R. Salyuk, A. Suess, Erwin Biebow, Nicole Salomatin, A. |
author_sort |
Obzhirov, A. |
title |
Relations between methane venting, geological structure and seismo-tectonics in the Okhotsk Sea |
title_short |
Relations between methane venting, geological structure and seismo-tectonics in the Okhotsk Sea |
title_full |
Relations between methane venting, geological structure and seismo-tectonics in the Okhotsk Sea |
title_fullStr |
Relations between methane venting, geological structure and seismo-tectonics in the Okhotsk Sea |
title_full_unstemmed |
Relations between methane venting, geological structure and seismo-tectonics in the Okhotsk Sea |
title_sort |
relations between methane venting, geological structure and seismo-tectonics in the okhotsk sea |
publisher |
Springer |
publishDate |
2004 |
url |
https://oceanrep.geomar.de/id/eprint/4157/ https://oceanrep.geomar.de/id/eprint/4157/1/Obzhirov.pdf https://doi.org/10.1007/s00367-004-0175-0 |
geographic |
Okhotsk |
geographic_facet |
Okhotsk |
genre |
okhotsk sea Sakhalin |
genre_facet |
okhotsk sea Sakhalin |
op_relation |
https://oceanrep.geomar.de/id/eprint/4157/1/Obzhirov.pdf Obzhirov, A., Shakirov, R., Salyuk, A., Suess, E., Biebow, N. and Salomatin, A. (2004) Relations between methane venting, geological structure and seismo-tectonics in the Okhotsk Sea. Geo-Marine Letters, 24 (3). pp. 135-139. DOI 10.1007/s00367-004-0175-0 <https://doi.org/10.1007/s00367-004-0175-0>. doi:10.1007/s00367-004-0175-0 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1007/s00367-004-0175-0 |
container_title |
Geo-Marine Letters |
container_volume |
24 |
container_issue |
3 |
_version_ |
1811643332548362240 |