scholarly journals Review of Methane Seepages in the Okinawa Trough: Progress and Outlook

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Ang Li ◽  
Qing Li ◽  
Cuiling Xu ◽  
Feng Cai ◽  
Hongbin Wang
Keyword(s):  
Okinawa Trough ◽  
Genomic Analysis ◽  
Future Research ◽  
Cold Seeps ◽  
Biogeochemical Processes ◽  
Methane Seeps ◽  
Methane Seepage ◽  
Geological Processes ◽  
The Okinawa Trough ◽  
Material Cycling

It has been two decades since the cold seeps were firstly found in the Okinawa Trough (OT). The scientific cruises and the geological surveys since then have unveiled the currently active submarine methane seeps and significantly improved the understanding of methane seeps in the back-arc basin of the OT. In this paper, we review the up-to-date progress of the research of methane seepages then put forward the promising, yet challenging, outlook by listing the unsolved questions of the cold seeps in the OT. Multiple approaches and techniques, including seismic and echo-sounder recording, dredging, gravity-piston and ROV coring, seafloor drilling, and isotopic and microarray-based genomic analysis, have been used to reveal the geological processes responsible for the seeping activities and the biogeochemical processes related to them. The geophysical signature associated with gas seeps mainly includes the acoustic turbidity in the subsurface, the anomaly of the backscattering intensity at the seabed, and the gas plumes observed in the water column. Pore water and methane-derived authigenic carbonate archive the intensification of methane seepage and the paleoenvironment changes at different time scales. The methane feeding of the seeps in the OT was generated mostly via the microbially mediated process and has an origin mixed by thermogenic hydrocarbon gas in the middle OT. Sulfate-driven and Fe-driven anaerobic oxidations of methane are suggested to be the key biogeochemical processes, which would shape the material cycling in the seeping environment. The future research on the cold seeps in the OT is worth looking forward to due to its geographic and potential geologic links with the nearby hydrothermal activities. Multidisciplinary studies are expected to concentrate on their link with the undiscovered gas hydrates, the amount of methane transferring into the oceans and its impact on the climatic change, and the evolution of the seeping activities accompanied by the biogeochemical processes.

The effect of methane seeps on the bacterial tetraether lipid distributions at the Okinawa Trough

2020 ◽  
Vol 225 ◽  
pp. 103845
Author(s):  
Zhe-Xuan Zhang ◽  
Jiwei Li ◽  
Zhiyan Chen ◽  
Zhilei Sun ◽  
Huan Yang ◽  
...  
Keyword(s):  
Okinawa Trough ◽  
Methane Seeps ◽  
Tetraether Lipid ◽  
The Okinawa Trough

scholarly journals Deepest and hottest hydrothermal activity in the Okinawa Trough: the Yokosuka site at Yaeyama Knoll

2017 ◽  
Vol 4 (12) ◽  
pp. 171570 ◽  
Author(s):  
Junichi Miyazaki ◽  
Shinsuke Kawagucci ◽  
Akiko Makabe ◽  
Ayu Takahashi ◽  
Kazuya Kitada ◽  
...  
Keyword(s):  
Hydrothermal Vents ◽  
Okinawa Trough ◽  
Water Pressure ◽  
Chemical Properties ◽  
Hydrothermal Activity ◽  
Future Research ◽  
Depth Range ◽  
Fluid Temperature ◽  
The Okinawa Trough ◽  
Ryukyu Arc

Since the initial discovery of hydrothermal vents in 1977, these ‘extreme’ chemosynthetic systems have been a focus of interdisciplinary research. The Okinawa Trough (OT), located in the semi-enclosed East China Sea between the Eurasian continent and the Ryukyu arc, hosts more than 20 known vent sites but all within a relatively narrow depth range (600–1880 m). Depth is a significant factor in determining fluid temperature and chemistry, as well as biological composition. However, due to the narrow depth range of known sites, the actual influence of depth here has been poorly resolved. Here, the Yokosuka site (2190 m), the first OT vent exceeding 2000 m depth is reported. A highly active hydrothermal vent site centred around four active vent chimneys reaching 364°C in temperature, it is the hottest in the OT. Notable Cl depletion (130 mM) and both high H 2 and CH 4 concentrations (approx. 10 mM) probably result from subcritical phase separation and thermal decomposition of sedimentary organic matter. Microbiota and fauna were generally similar to other sites in the OT, although with some different characteristics. In terms of microbiota, the H 2 -rich vent fluids in Neuschwanstein chimney resulted in the dominance of hydrogenotrophic chemolithoautotrophs such as Thioreductor and Desulfobacterium . For fauna, the dominance of the deep-sea mussel Bathymodiolus aduloides is surprising given other nearby vent sites are usually dominated by B. platifrons and/or B. japonicus , and a sponge field in the periphery dominated by Poecilosclerida is unusual for OT vents. Our insights from the Yokosuka site implies that although the distribution of animal species may be linked to depth, the constraint is perhaps not water pressure and resulting chemical properties of the vent fluid but instead physical properties of the surrounding seawater. The potential significance of these preliminary results and prospect for future research on this unique site are discussed.

scholarly journals Occurrence and recent long-distance dispersal of deep-sea hydrothermal vent shrimps

2005 ◽  
Vol 2 (2) ◽  
pp. 257-260 ◽  
Author(s):  
Gaku Tokuda ◽  
Akinori Yamada ◽  
Kazuma Nakano ◽  
Nao Arita ◽  
Hideo Yamasaki
Keyword(s):  
Deep Sea ◽  
Hydrothermal Vent ◽  
Hydrothermal Vents ◽  
Okinawa Trough ◽  
Rrna Gene ◽  
Cold Seeps ◽  
Long Distance Dispersal ◽  
High Concentration ◽  
Long Distance ◽  
The Okinawa Trough

Deep-sea hydrothermal vents and methane seeps are extreme environments that have a high concentration of hydrogen sulphide. However, abundant unique invertebrates including shrimps of the family Bresiliidae have been found in such environments. The bresiliid shrimps are believed to have radiated in the Miocene (less than 20 Myr); however, the period when and the mechanisms by which they dispersed across the hydrothermal vents and cold seeps in oceans worldwide have not been clarified. In the present study, we collected the deep-sea blind shrimp Alvinocaris longirostris from the hydrothermal vent site in the Okinawa Trough and carried out the first investigation of the 18S rRNA gene of a bresiliid shrimp. The phylogenetic analysis revealed that the bresiliid shrimp is situated at an intermediate lineage within the infraorder Caridea and shows monophyly with palaemonid shrimps, which live in shallow sea and freshwater. Furthermore, the mitochondrial cytochrome oxidase I ( COI ) gene sequences were analysed to determine the phylogenetic relationship with known bresiliid shrimps. A. longirostris of the Okinawa Trough had two haplotypes of the COI gene, one of which was identical to the Alvinocaris sp. of the cold seeps in Sagami Bay. These results indicate that a long-distance dispersal of A. longirostris occurred possibly within the last 100 000 years.

Characteristics of hydrocarbons in hydrothermal products of the Clam hydrothermal field from the Okinawa trough

2021 ◽  
Vol 167 ◽  
pp. 112277
Author(s):  
Xin Huang ◽  
Chao Huang ◽  
Yali Qi ◽  
Xiaoyuan Wang ◽  
Hansheng Cao
Keyword(s):  
Okinawa Trough ◽  
Hydrothermal Field ◽  
The Okinawa Trough

Element enrichment and U-series isotopic characteristics of the hydrothermal sulfides at Jade site in the Okinawa Trough

2009 ◽  
Vol 52 (7) ◽  
pp. 913-924 ◽  
Author(s):  
ZhiGang Zeng ◽  
ShaoXiong Yu ◽  
XueBo Yin ◽  
XiaoYuan Wang ◽  
GuoLiang Zhang ◽  
...  
Keyword(s):  
Okinawa Trough ◽  
The Okinawa Trough ◽  
Element Enrichment ◽  
Hydrothermal Sulfides

EXPRESS: A Piecewise Model for In Situ Raman Measurement of the Chlorinity of Deep-Sea High-Temperature Hydrothermal Fluids

2021 ◽  
pp. 000370282199911
Author(s):  
meng ge ◽  
Lianfu Li ◽  
Xin Zhang ◽  
Zhendong Luan ◽  
Zengfeng Du ◽  
...  
Keyword(s):  
High Temperature ◽  
Deep Sea ◽  
Okinawa Trough ◽  
Peak Position ◽  
Hydrothermal Fluids ◽  
Calibration Model ◽  
The Okinawa Trough ◽  
Temperature Ranges ◽  
Piecewise Model ◽  
C 50

The chlorinity of deep-sea hydrothermal fluids, representing one of the crucial deep-sea hydrothermal indicators, indicates the degree of deep phase separation of hydrothermal fluids and water/rock reactions. However, accurately measuring the chlorinity of high-temperature hydrothermal fluids is still a significant challenge. In this paper, a piecewise chlorinity model to measure the chlorinity of high-temperature hydrothermal fluids was developed based on the OH stretching band of water, exhibiting an accuracy of 96.20%. The peak position, peak area ratio and F value were selected to establish the chlorinity piecewise calibration model within the temperature ranges of 0-50°C, 50-200°C and 200-300°C. Compared with that of the chlorinity calibration model built based on a single parameter, the accuracy of this piecewise model increased by approximately 4.83-12.33%. This chlorinity calibration model was applied to determine the concentrations of Cl for high-temperature hydrothermal fluids in the Okinawa Trough hydrothermal field.

Helium isotopes in volcanic rocks from the Okinawa Trough-impact of volatile recycling and crustal contamination

2016 ◽  
Vol 51 ◽  
pp. 376-386 ◽  
Author(s):  
Zenghui Yu ◽  
Shikui Zhai ◽  
Kun Guo ◽  
Yonghua Zhou ◽  
Tong Zong
Keyword(s):  
Okinawa Trough ◽  
Volcanic Rocks ◽  
Crustal Contamination ◽  
Helium Isotopes ◽  
The Okinawa Trough
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