Japan Geoscience Union Meeting 2019

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[E] Poster

S (Solid Earth Sciences ) » S-CG Complex & General

[S-CG48] Science of slow earthquakes: Toward unified understandings of whole earthquake process

Wed. May 29, 2019 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall8, Makuhari Messe)

convener:Satoshi Ide(Department of Earth an Planetary Science, University of Tokyo), Hitoshi Hirose(Research Center for Urban Safety and Security, Kobe University), Kohtaro Ujiie(Graduate School of Life and Environmental Sciences, University of Tsukuba), Takahiro Hatano(Earthquake Research Institute, University of Tokyo)

[SCG48-P24] A new hydrothermal, low to high speed rotary-shearing apparatus: Reproduction of slow/megathrust earthquakes in laboratory

*Takehiro Hirose1, Wataru Tanikawa1, Yohei Hamada1, Keishi Okazaki1 (1.Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology)

Keywords:friction, hydrothermal, slow to fast slip

Earthquakes involve a wide range of slip rates, from slow/aseismic to fast/seismic slip along faults. Thus, frictional properties of faults over wide slip rates (nm/s to m/s), in particular under hydrothermal conditions similar to those expected in seismogenic zones are essential for a unified understanding of all earthquake events. A new hydrothermal, low to high speed rotary-shearing apparatus has been installed at Kochi/JAMSTEC, in order to study the fault constitutive properties at slow to fast slip rates and the physicochemical mechanisms underlying mechanical responses. The apparatus is currently capable of applying slip rates from 100 nm/s to 2 m/s, normal stress up to 55 MPa, fluid pressure up to 120 MPa and temperature up to 450oC with infinite displacement. We have been improving the apparatus to work as we intended. In pilot tests, we used metamorphic rocks (pelitic and green schists) as starting materials that are potentially distributed at and below seismogenic zones along hot and young subduction zones. We will present our preliminary results with the basic design of the apparatus.