排序方式: 共有36条查询结果,搜索用时 15 毫秒
31.
T. Matveeva V. Soloviev K. Wallmann A. Obzhirov N. Biebow J. Poort A. Salomatin H. Shoji 《Geo-Marine Letters》2003,23(3-4):278-288
Geochemical properties of gas hydrate accumulation associated with an active gas vent on the continental slope offshore northeast Sakhalin Island in the Sea of Okhotsk have been investigated. The pore water chemistry data suggest that the gas hydrates (GHs) were formed in an environment of upward-migrating fluid combined with a mechanism of pore water segregation. The upward infiltration of water enriched mainly by Cl– and K+ species appears to occur on the background of earlier diagenesis processes within the gas vent sediments. The GHs were formed from water with chlorinity ranging from 530 to 570 mM. The 18O and D of GH water varied from –1.4 to –1.8 and from –13 to –18, respectively, representing a mix of seawater and infiltrating fluid water. A complex interaction of pore water, water of ascending fluid and segregated pore water during hydrate formation is also supported by water content measurements and observed gas hydrate structure. The direction of segregated water is opposite to upward fluid migration. Decreasing activity of the gas vent is inferred by comparing the present top of the recovered hydrate layer with previous observations. 相似文献
32.
Characteristics of shallow gas hydrate in Okhotsk Sea 总被引:1,自引:0,他引:1
LUAN XiWu JIN YoungKeun Anatoly OBZHIROV YUE BaoJing Key Lab of Marine Geology Environment Institute of Oceanology Chinese Academy of Sciences Qingdao China Korea Polar Research Institute KORDI Incheon - Korea V.I. Il’ichev Pacific Oceanological Institute of the Far Eastern Branch of Russian Academy of Sciences Vladivostok Russia 《中国科学D辑(英文版)》2008,51(3):415-421
Multidisciplinary field investigations were carried out in Okhotsk Sea by R/V Akademik M.A. Lavrentyev (LV) of the Russian Academy of Sciences (RAS) in May 2006, supported by funding agencies from Ko- rea, Russia, Japan and China. Geophysical data including echo-sounder, bottom profile, side-scan- sonar, and gravity core sample were obtained aimed to understand the characteristics and formation mechanism of shallow gas hydrates. Based on the geophysical data, we found that the methane flare detected by echo-sounder was the evidence of free gas in the sediment, while the dome structure de- tected by side-scan sonar and bottom profile was the root of gas venting. Gas hydrate retrieved from core on top of the dome structure which was interbedded as thin lamination or lenses with thickness varying from a few millimeters to 3 cm. Gas hydrate content in hydrate-bearing intervals visually amounted to 5%―30% of the sediment volume. This paper argued that gases in the sediment core were not all from gas hydrate decomposition during the gravity core lifting process, free gases must existed in the gas hydrate stability zone, and tectonic structure like dome structure in this paper was free gas central, gas hydrate formed only when gases over-saturated in this gas central, away from these struc- tures, gas hydrate could not form due to low gas concentration. 相似文献
33.
Doklady Earth Sciences - High variability in methane fluxes at the water–atmosphere boundary was found for the first time for the period 1990–2016 using expeditionary data. Variability... 相似文献
34.
A. I. Gresov A. I. Obzhirov A. V. Yatsuk A. K. Mazurov A. S. Ruban 《Russian Journal of Pacific Geology》2017,11(4):308-314
The work reports on the results of geochemical studies of the bottom sediments on the shelf of the East Siberian Sea. The sediments’ gas content, gas composition, and gas geochemical and isotopic characteristics are determined. Abnormal zones of distribution of methane, hydrocarbon gases, and carbon dioxide are revealed within the studied areas, along with the general geological factors affecting gas formation. Areas of distribution of hydrocarbon gases of varying origins are distinguished. The potential for oil-and-gas content is estimated. 相似文献
35.
Obzhirov A. I. Polonik N. S. Ponomareva A. L. Vereshchagina O. V. Telegin Yu. A. Syrbu N. S. Flint M. V. 《Oceanology》2021,61(6):881-891
Oceanology - Estimates of the content of dissolved methane, hydrogen, and helium in seawater of the Kara Sea were obtained. It was found that the methane concentration in the studied areas varied... 相似文献
36.
Oceanology - The paper presents the first data on the methane distribution in the water column of Antarctic Sound (Atlantic sector of the Southern Ocean) acquired during an integrated expedition of... 相似文献