scholarly journals New insights into deformation and fluid flow processes in the Nankai Trough accretionary prism: Results of Ocean Drilling Program Leg 190

2001 ◽  
Vol 2 (10) ◽  
pp. n/a-n/a ◽  
Author(s):  
Gregory F. Moore ◽  
Asahiko Taira ◽  
Adam Klaus ◽  
Luann Becker ◽  
Babette Boeckel ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Nankai Trough ◽  
Accretionary Prism ◽  
Ocean Drilling Program ◽  
Ocean Drilling ◽  
Flow Processes

scholarly journals Microbial Community Stratification Controlled by the Subseafloor Fluid Flow and Geothermal Gradient at the Iheya North Hydrothermal Field in the Mid-Okinawa Trough (Integrated Ocean Drilling Program Expedition 331)

2014 ◽  
Vol 80 (19) ◽  
pp. 6126-6135 ◽  
Author(s):  
Katsunori Yanagawa ◽  
Anja Breuker ◽  
Axel Schippers ◽  
Manabu Nishizawa ◽  
Akira Ijiri ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Microbial Communities ◽  
Okinawa Trough ◽  
Geothermal Gradient ◽  
Hydrothermal Field ◽  
Rrna Gene ◽  
Ocean Drilling Program ◽  
Content Type ◽  
Ocean Drilling ◽  
Integrated Ocean Drilling Program

ABSTRACTThe impacts of lithologic structure and geothermal gradient on subseafloor microbial communities were investigated at a marginal site of the Iheya North hydrothermal field in the Mid-Okinawa Trough. Subsurface marine sediments composed of hemipelagic muds and volcaniclastic deposits were recovered through a depth of 151 m below the seafloor at site C0017 during Integrated Ocean Drilling Program Expedition 331. Microbial communities inferred from 16S rRNA gene clone sequencing in low-temperature hemipelagic sediments were mainly composed of members of theChloroflexiand deep-sea archaeal group. In contrast, 16S rRNA gene sequences of marine group IThaumarchaeotadominated the microbial phylotype communities in the coarse-grained pumiceous gravels interbedded between the hemipelagic sediments. Based on the physical properties of sediments such as temperature and permeability, the porewater chemistry, and the microbial phylotype compositions, the shift in the physical properties of the sediments is suggested to induce a potential subseafloor recharging flow of oxygenated seawater in the permeable zone, leading to the generation of variable chemical environments and microbial communities in the subseafloor habitats. In addition, the deepest section of sediments under high-temperature conditions (∼90°C) harbored the sequences of an uncultivated archaeal lineage of hot water crenarchaeotic group IV that may be associated with the high-temperature hydrothermal fluid flow. These results indicate that the subseafloor microbial community compositions and functions at the marginal site of the hydrothermal field are highly affected by the complex fluid flow structure, such as recharging seawater and underlying hydrothermal fluids, coupled with the lithologic transition of sediments.

scholarly journals The IODP Expedition 332 : Eyes on the Prism, The NanTroSEIZE Observatories

2012 ◽  
Vol 14 ◽  
pp. 34-38 ◽  
Author(s):  
S. T. Toczko ◽  
A. J. Kopf ◽  
E. Araki ◽  
Keyword(s):  
Nankai Trough ◽  
Temperature Data ◽  
Seismogenic Zone ◽  
Plate Boundaries ◽  
Transient Pressure ◽  
Ocean Drilling Program ◽  
Ocean Drilling ◽  
Integrated Ocean Drilling Program ◽  
Drilling Project

The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) is a major long-term drilling project designed to investigate the seismogenic behavior of subduction zone plate boundaries. Integrated Ocean Drilling Program (IODP) Expedition 332 deployed a long-term borehole monitoring system (LTBMS), an advanced Circulation Obviation Retrofit Kit (CORK)-type observatory. The recovery of pressure and temperature data from a temporary observatory (SmartPlug) deployed during IODP Expedition 319 helped prove the SmartPlug concept. The permanent LTBMS was deployed n the upper 1000 m of Site C0002, while the SmartPlug was recovered from Site C0010 and replaced with a more capable "GeniusPlug", incorporating an extension with a geochem-ical sampler and biological experiment to the original SmartPlug design. SmartPlug pressure and temperature data showed signs of transient pressure events. <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.14.04.2012" target="_blank">10.2204/iodp.sd.14.04.2012</a>

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