| Gas seepage on the sea floor of Okinawa Trough Miyako Section |
| Luan, XW; Qin, YS
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| 2005-07-01
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| 发表期刊 | CHINESE SCIENCE BULLETIN
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| ISSN | 1001-6538
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| 卷号 | 50期号:13页码:1358-1365 |
| 文章类型 | Article
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| 摘要 | A marine geophysical survey was carried out, on the RN Science 1 of the Institute of Oceanography, Chinese Academy of Sciences (IOCAS), in 2000, at the Miyako Section of Okinawa Trough. Here we present seismic and acoustic evidence of a gas seep on the sea floor on the western part of the Okinawa Through, near the lower slope of the East China Sea Slope and discuss the possibility of related formation of gas hydrate. A gas column reflection was observed in echo-sounder data above a section where the sea floor reflector was missing, on both the echo-sounder and the seismic data for line H14. The seismic data also show an acoustic curtain reflection and a turbidity reflection at this section. These anomalies are the evidence of the existence of a gas seep, which occupies an area 2.2 km in diameter. Based on the acoustic curtain on line H14, we believe that the amount of gas contained in the sediments below the gas seep is larger than 1 % by volume of sediment. Tectonically, the gas seep developed in a small basin controlled by basement uplift in the north, south and east. The thickness of the sediment layer can be greater than 3.5 km. A mud diapir structure was found in layer D beneath the gas seep. Over-pressure may occur due to the large sediment thickness and also the tectonic basement uplift in the north, south, and east. The mud diapir could be the preferential pathway for methane-rich fluids. The acoustic curtain may indicate that free gas related to the gas seep can be formed on the sea floor. We also note that the layer above the acoustic curtain on profile H14 may contain gas hydrate.; A marine geophysical survey was carried out, on the RN Science 1 of the Institute of Oceanography, Chinese Academy of Sciences (IOCAS), in 2000, at the Miyako Section of Okinawa Trough. Here we present seismic and acoustic evidence of a gas seep on the sea floor on the western part of the Okinawa Through, near the lower slope of the East China Sea Slope and discuss the possibility of related formation of gas hydrate. A gas column reflection was observed in echo-sounder data above a section where the sea floor reflector was missing, on both the echo-sounder and the seismic data for line H14. The seismic data also show an acoustic curtain reflection and a turbidity reflection at this section. These anomalies are the evidence of the existence of a gas seep, which occupies an area 2.2 km in diameter. Based on the acoustic curtain on line H14, we believe that the amount of gas contained in the sediments below the gas seep is larger than 1 % by volume of sediment. Tectonically, the gas seep developed in a small basin controlled by basement uplift in the north, south and east. The thickness of the sediment layer can be greater than 3.5 km. A mud diapir structure was found in layer D beneath the gas seep. Over-pressure may occur due to the large sediment thickness and also the tectonic basement uplift in the north, south, and east. The mud diapir could be the preferential pathway for methane-rich fluids. The acoustic curtain may indicate that free gas related to the gas seep can be formed on the sea floor. We also note that the layer above the acoustic curtain on profile H14 may contain gas hydrate. |
| 关键词 | Okinawa Trough
Gas Seepage
Evidences
Formation
Gas Hydrate
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| 学科领域 | Multidisciplinary Sciences
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| DOI | 10.1360/04wd0257
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| 收录类别 | SCI
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| 语种 | 英语
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| WOS记录号 | WOS:000231858000012
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| 引用统计 |
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| 文献类型 | 期刊论文
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| 条目标识符 | http://ir.qdio.ac.cn/handle/337002/3744
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| 专题 | 海洋地质与环境重点实验室
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| 作者单位 | Chinese Acad Sci, Inst Oceanog, Qingdao 266071, Peoples R China
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推荐引用方式
GB/T 7714 |
Luan, XW,Qin, YS. Gas seepage on the sea floor of Okinawa Trough Miyako Section[J]. CHINESE SCIENCE BULLETIN,2005,50(13):1358-1365.
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| APA |
Luan, XW,&Qin, YS.(2005).Gas seepage on the sea floor of Okinawa Trough Miyako Section.CHINESE SCIENCE BULLETIN,50(13),1358-1365.
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| MLA |
Luan, XW,et al."Gas seepage on the sea floor of Okinawa Trough Miyako Section".CHINESE SCIENCE BULLETIN 50.13(2005):1358-1365.
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