Sulphur-isotopic composition of the deep-sea mussel Bathymodiolus marisindicus from currently active hydrothermal vents in the Indian Ocean

Sulphur-isotopic composition of soft tissues from bathymodiolus marisindicus collected from hydrothermal vents in the indian ocean was reported. the [delta]34s values of the soft tissues (+3[similar]+5‰ vs cañyon diablo troilite) were nearly identical to those from the associated hydrothermal fluid and chimney sulphides (+5 to +8‰), but were significantly different from that of the common seawater sulphate (+21‰), which suggested that the endosymbiotic bacteria used sulphide in the fluid as an energy source. transmission electron microscopic observation of the endosymbionts also suggested that the symbiont is a thioautotroph. bathymodiolus species, which depend on either sulphide or methane oxidation, or both, have a worldwide distribution. bathymodiolus marisindicus from the indian ocean has a close relationship with congeners in the pacific ocean as evidenced by form of symbiosis. biogeography and migration of the genus bathymodiolus based on the relevant data are briefly discussed.</p

The recent distribution of lead in the Indian Ocean reflects the impact of regional emissions

Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of American 111 (2014): 15328–15331, doi:10.1073/pnas.1417370111Humans have injected lead (Pb) massively into the earth surface environment in a temporally and spatially evolving pattern. A significant fraction is transported by the atmosphere into the surface ocean where we can observe its transport by ocean currents and sinking particles. This study of the Indian Ocean documents high Pb concentrations in the northern and tropical surface waters, and extremely low Pb levels in the deep water. North of 20°S, dissolved Pb concentrations decrease from 42-82 pmol/Kg in surface waters to 1.5-3.3 pmol/Kg in deep waters. South of 20°S, surface water Pb concentrations decrease from 21 pmol/Kg at 31°S to 7 pmol/Kg at 62°S. This surface Pb concentration gradient reflects a southward decrease in anthropogenic Pb emissions. The upper waters of the north and central Indian Ocean have high Pb concentrations resulting from recent regional rapid industrialization and a late phase-out of leaded gasoline, and these concentrations are now higher than currently seen in the central North Pacific and North Atlantic Oceans. The Antarctic sector of the Indian Ocean shows very low concentrations due to limited regional anthropogenic Pb emissions, high scavenging rates, and rapid vertical mixing, but Pb still occurs at higher levels than would have existed centuries ago. Penetration of Pb into the northern and central Indian Ocean thermocline waters is minimized by limited ventilation. Pb concentrations in the deep Indian Ocean are comparable to the other oceans at the same latitude, and deep waters of the central Indian Ocean match the lowest observed oceanic Pb concentrations.Y. Echegoyen thanks the Spanish Ministry of Science and Innovation for a postdoctoral MEC-Fulbright grant. MIT laboratory expenses were supported by a grant from the Singapore National Research Foundation to the SMART-CENSAM project. Sample collection was supported by grants from the Steel Foundation for Environmental Protection Technology and from Grant-in-Aid of Scientific Research, the Ministry of Education, Culture, Sports, Science, and Technology of Japan

The GEOTRACES Intermediate Data Product 2014

The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEIs) as well as classical hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing a strongly inter-linked on-line atlas including more than 300 section plots and 90 animated 3D scenes. The IDP2014 covers the Atlantic, Arctic, and Indian oceans, exhibiting highest data density in the Atlantic. The TEI data in the IDP2014 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at cross-over stations. The digital data are provided in several formats, including ASCII spreadsheet, Excel spreadsheet, netCDF, and Ocean Data View collection. In addition to the actual data values the IDP2014 also contains data quality flags and 1-? data error values where available. Quality flags and error values are useful for data filtering. Metadata about data originators, analytical methods and original publications related to the data are linked to the data in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2014 data providing section plots and a new kind of animated 3D scenes. The basin-wide 3D scenes allow for viewing of data from many cruises at the same time, thereby providing quick overviews of large-scale tracer distributions. In addition, the 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of observed tracer plumes, as well as for making inferences about controlling processes

(Geotraces) Meridional studies on biogeochemistry of trace elements and isotopes in the indian ocean

航海番号: KH-09-5 Leg 1, Leg 2, Leg 3 ; 航海日程: November 6, 2009 - January 9, 201

(Geotraces) Zonal studies on Biogeochemistry of trace elements and isotopes in the sub-arctic north pacific ocean

航海番号: KH-12-4 ; 航海日程: August 23, 2012 - October 3, 201

(Piscis Austrinus expedition) Studies on ocean flux in the Eastern Indian Ocean and its adjacent seas

航海番号: KH-96-5 ; 航海日程: December 19, 1996 - February 18, 199

Origins of hydrocarbons in the Sagara oil field, central Japan

We collected free-gas and in situ fluid samples up to a depth of 200.6 m from the Sagara oil field, central Japan (34°44′N, 138°15′E), during the Sagara Drilling Program (SDP) and measured the concentrations and stable carbon isotopic compositions of CH4 and C2H6 in the samples. A combination of the CH4/C2H6 ratios with the carbon isotope ratios of methane indicates that the hydrocarbon gases are predominantly of thermogenic origin at all depths. The isotope signature of hydrocarbon gases of δ13CCH4 < δ13CC2H6 suggests that these gases in the Sagara oil field are not generated by polymerization, but by the decomposition of organic materials