YIN Xijie, ZHOU Huaiyang, YANG Qunhui, WANG Hu, CHEN Jian. The evidence for the existence of methane seepages in the northern South China Sea: abnormal high methane concentrations in bottom waters[J]. Acta Oceanologica Sinica, 2008, (6): 62-70.
Citation:
YIN Xijie, ZHOU Huaiyang, YANG Qunhui, WANG Hu, CHEN Jian. The evidence for the existence of methane seepages in the northern South China Sea: abnormal high methane concentrations in bottom waters[J]. Acta Oceanologica Sinica, 2008, (6): 62-70.
YIN Xijie, ZHOU Huaiyang, YANG Qunhui, WANG Hu, CHEN Jian. The evidence for the existence of methane seepages in the northern South China Sea: abnormal high methane concentrations in bottom waters[J]. Acta Oceanologica Sinica, 2008, (6): 62-70.
Citation:
YIN Xijie, ZHOU Huaiyang, YANG Qunhui, WANG Hu, CHEN Jian. The evidence for the existence of methane seepages in the northern South China Sea: abnormal high methane concentrations in bottom waters[J]. Acta Oceanologica Sinica, 2008, (6): 62-70.
Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China;Graduate School, Chinese Academy of Sciences, Beijing 100049, China
2.
Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China;State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China
3.
Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China
The methane concentration of water samples at five stations collected by the CTD rosette water sampler in the areas of southwest Dongsha Islands and the Xisha Trough was analyzed by the gas-stripping method on aboard ship. It shows abnormal high methane concentrations in near bottom water samples at three stations. In the southwest Dongsha Islands area, the methane concentration of 4.25 and 10.64 nmol/dm3 occurs in near bottom water samples at Stas E105A and E106, respectively. In the Xisha Trough area, the high methane concentrations of 5.17, 8.48 and 8.70 nmol/dm3 in water depths of 1 750, 1 900 and 2 050 m, respectively, have been observed at Sta. E413. It is believed that the abnormal high methane concentrations are generated from the leakage of methane from sediments. Combining with previous geophysical and geochemical data from these two areas, this was probably related to the submarine gas hydrates decomposition and cold seep system. In May 2007, gas hydrate samples were successfully obtained by the drilling in the Shenhu Sea area located in the southwest Dongsha Islands area. It is called for further drilling surveys to confirm the existence of gas hydrate and cold seep system in the Xisha Trough as early as possible.