J-DESCはJOIDES Resolutionにて実施されるIODP Exp. 344 Costa Rica Seismogenesis Project 2 (CRISP2)とExp. 345 Hess Deep Plutonic Crustの乗船研究者を募集いたします。
Costa Rica Seismogenesis Project 2 (CRISP 2)
IODP Expedition 344; 2012年10月～12月
Based on Expedition 334 and Proposals 537A-Full5 and 537A-Add,this expedition aims to understand the processes that control nucleation and seismic rupture of large earthquakes at erosional subduction zones. Scientific objectives include (1) the characterization of the lithology,texture,and physical properties of the subducting sediments and basement;(2) the rate of subduction erosion and subsidence history of the upper plate;(3) the fluid/rock interactions and geochemical processes active within the upper plate;and (4) the evolution of the stress field upslope.
Hess Deep Plutonic Crust
IODP Expedition 345; 2012年12月～2013年2月
Based on IODP Proposals 551-Full and 551-Add,this expedition aims to understand the nature of gabbroic rocks that formed at the fast-spreading East Pacific Rise (EPR) and test competing hypotheses of magmatic accretion and hydrothermal processes in the lower ocean crust. The scientific objectives will address (1) the architecture of the oceanic crust inferred from ophiolites and geophysical observations along modern fast-spreading ridges,and (2) the extent and nature of heat and mass fluxes between the asthenosphere,lithosphere,and hydrosphere reservoirs. This includes (1) how is the lower ocean crust accreted at fast-spreading ridges,and how does this relate to the differentiation of mid-ocean ridge basalts;(2) where,when,and at what temperature do hydrothermal fluids penetrate into the lower oceanic crust,and what effect do these have on the heat and chemical budgets near the ridge axis;and (3) how quickly does the lower oceanic crust cool,what is the thermal structure at the ridge axis,and how do the magmatic and hydrothermal systems interact to determine the thermal regime.