A5044416674- Methane Hydrates and Related Phenomena
- Geology and Paleoclimatology Research
- Isotope Analysis in Ecology
- Hydrocarbon exploration and reservoir analysis
- Marine Biology and Ecology Research
- Astro and Planetary Science
- Geological and Geophysical Studies
- Paleontology and Stratigraphy of Fossils
- Planetary Science and Exploration
- Offshore Engineering and Technologies
- Marine Bivalve and Aquaculture Studies
- Microbial Community Ecology and Physiology
- Geophysics and Gravity Measurements
- Astronomical Observations and Instrumentation
- Geological and Geochemical Analysis
- Geomagnetism and Paleomagnetism Studies
- Geological Studies and Exploration
- Spacecraft and Cryogenic Technologies
- Geological formations and processes
- Archaeology and ancient environmental studies
- Geochemistry and Elemental Analysis
- Pacific and Southeast Asian Studies
- earthquake and tectonic studies
- Marine and coastal ecosystems
- Geochemistry and Geologic Mapping
Tokyo University of Marine Science and Technology
2018-2024
Museum of Natural and Environmental History, Shizuoka
2022
Okayama University
2011-2021
International Ocean Discovery Program
2021
Nagasaki Institute of Applied Science
2018
Okayama University of Science
2008-2016
Kyushu University
1999-2012
Kyoto University
2012
Mifune Dinosaur Museum
2012
Iwate University
2003-2011
Geochemical characteristics of hydrothermal fluids in the Iheya North field, mid-Okinawa Trough, was investigated. Twelve-years observation reveals temporal variation vent fluid chemistry potentially controlled by temporally varying pattern phase-separation and -segregation, while constant Element/Cl ratios among periods chimneys indicate stable chemical composition source prior to undergoing phase-separation. The high K contents estimated are typical arc-backarc systems due reaction with...
Abstract We report the first study of sperm whale‐fall ecosystems, based on mass sinking whale carcasses at shelf depths in northwest Pacific. conducted three observations over a 2‐year period replicate sperm‐whale implanted 219–254 m off southern part Japan from July 2003 to August 2005. The was made possible by stranding whales January 2002, and subsequent 12 waters Cape Nomamisaki. Dense aggregations unique chemosynthesis‐based fauna had formed around after 18 months (July 2003). mytilid...
Two active hydrothermal fields, Jade and Hakurei fields have been discovered within the Izena Hole, a rectangular 6 km × 3 shape depression located in middle Okinawa Trough back arc basin. In both intense activity is represented by venting of high-temperature fluid (>300°C) occurrence sulfide/sulfate ore deposits. We collected fluids during dive expeditions ROV Hyper Dolphin conducted 2003, 2010 2011, order to analyze elemental gas species. The geochemistry high temperature from very similar...
Abstract Heat flow is estimated at eight sites drilled int the Guaymas Basin, Gulf of California, during International Ocean Discovery Program Expedition 385. The expedition sought to understand thermal regime basin and heat transfer between off‐axis sills intruding organic‐rich sediments floor. distinct sedimentation rates, active tectonics, magmatism make interesting for scientific discoveries. Results show that corrected values range 119–221 mW/m 2 in 257–1003 site a young sill intrusion,...
Thriving chemosynthetic communities were located for the first time in Indian Ocean between 2420 and 2450 m, on a volcanic knoll at eastern crest of an axial valley, approximately 22 km north Rodriguez Triple Junction. The distributed 40m by 80m field around knoll. At least seven active vent sites, including black smoker complexes that emitting superheated water 360°C, observed field. faunal composition hydrothermal had links to both Pacific Atlantic assemblages. This discovery supports...
Summary To extend knowledge of subseafloor microbial communities within the oceanic crust, abundance, diversity and composition in crustal fluids at back‐arc hydrothermal fields Southern Mariana Trough (SMT) were investigated using culture‐independent molecular techniques based on 16S rRNA gene sequences. Seafloor drilling was carried out two fields, on‐ off‐ridge spreading centre SMT. clone libraries for bacterial archaeal constructed from fluid samples collected boreholes. Phylotypes...
Abstract During mid-Cretaceous Oceanic Anoxic Event 2, significant increase of atmospheric carbon dioxide concentrations from the eruption large igneous provinces is hypothesized to have induced a humid climate and an elevation in nutrient runoff continents oceans, resulting oxygen depletion ocean. However, hitherto there limited insight into driving factors 2 Pacific Asian continental margins, even though former latter were largest ocean landmass at that time. Here, multiproxy analysis for...
Viruses play important roles in marine surface ecosystems, but little is known about viral ecology and virus-mediated processes deep-sea hydrothermal microbial communities. In this study, we examined virus-like particle (VLP) abundances planktonic attached communities, which occur physical chemical gradients both deep shallow submarine environments (mixing waters between fluids ambient seawater dense communities to chimney areas or macrofaunal bodies colonies). We found that viruses were...
The discovery and description of cold seeps with deep-sea chemosynthetic communities in the Southwest Atlantic Ocean are still incomplete, despite large proven oil gas reserves off coast Brazil. In southeastern Brazilian continental margin, where over 71% country's production takes place, there previous geological qualitative biological evidence seep biota associated pockmarks on upper slope Santos Basin. order to further study ecosystems a investigation named Iatá-Piúna cruise was conducted...
Brucite-carbonate chimneys were discovered from the deepest known (∼5700 m depth) serpentinite-hosted ecosystem—the Shinkai Seep Field (SSF) in southern Mariana forearc. Textural observations and geochemical analysis reveal three types (I–III) of formed by precipitation dissolution constitutive minerals. Type I are bright white to light yellow, have a spiky crystalline wrinkled surface with microbial mat contain more brucite; these as result rapid under high fluid discharge conditions. II...
ABSTRACT This study describes the occurrence of unique dissimilatory sulfite reductase (DSR) genes at a depth 1,380 m from deep-sea hydrothermal vent field Suiyo Seamount, Izu-Bonin Arc, Western Pacific, Japan. The DSR were obtained microbes that grew in catheter-type situ growth chamber deployed for 3 days on and effluent water drilled holes 5°C natural fluids 7°C. clones SUIYOdsr-A SUIYOdsr-B not closely related to cultivated species or environmental clones. Moreover, samples microbial...
Background Deep-sea mussels harboring chemoautotrophic symbionts from hydrothermal vents and seeps are assumed to have evolved shallow-water asymbiotic relatives by way of biogenic reducing environments such as sunken wood whale falls. Such symbiotic associations been well characterized in collected vents, but only a few Methodology/Principal Finding Here we report symbioses the gill tissues two mussels, Adipicola crypta pacifica, whale-falls on continental shelf northwestern Pacific. The...
The galatheid crab Shinkaia crosnieri , is the sole member of subfamily Shinkaiinae. It abundant and forms dense beds around active hydrothermal vents in Okinawa Trough. Thousands filamentous bacteria attached to plumose setae on ventral surface this were observed using field-emission scanning electron microscopy transmission microscopy. Nucleic acids extracted from bacteria, phylotypes 16S rRNA genes identified 81 clones. These divided into three groups: Epsilonproteobacteria (74%);...
Chemical and isotopic compositions of hydrothermal fluids from Hatoma Knoll in the southern Okinawa Trough were investigated. The derived a single pure fluid source, but they underwent phase separation beneath seafloor prior to venting. Only vapor-like vent at system, most active area is around center crater, based on location maximum temperature lowest Cl– concentrations. Compared with other systems world, pH alkalinity, as well B, NH4+, K, Li, CO2, CH4 concentrations, higher, Fe Al...