JAMSTEC > Research Institute for Value-Added-Information Generation (VAiG) > Center for Mathematical Science and Advanced Technology (MAT) > Member > Osamu Kuwano

Center for Mathematical Science and Advanced Technology (MAT)

Members

Osamu Kuwano

photo

Scientist
Japan Agency for Marine-Earth Science and Technology
Center for Mathematical Science and Advanced Technology

3173-25, Showa-machi, Kanazawa-ku, Yokohama-city, Kanagawa, 236-0001, Japan
kuwano_at_jamstec.go.jp


Short CV

Research Interests: Friction and fracture of granular matter, rocks and faults / Experimental earthquake physics

Employment

2012.4 - present Scientist, Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
2008.4 - 2012.3 Project Researcher, University of Tokyo
2005.4 - 2008.3 JSPS Research Fellow (DC1), University of Tokyo
2015.4 - 2016.3 Part-time Lecturer, Utsunomiya University

Education

University of Tokyo (Ph.D., 2008; M.S., 2005; B.S., 2003, in Geophysics)

Grants

FY2016 - FY2017 JSPS Grant-in-Aid for challenging Exploratory Research, #16K13877 (PI)
FY2015 - FY2016 JSPS Grant-in-Aid for challenging Exploratory Research, #15K13561 (Co)
FY2014 - FY2016 JAMSEC Grant‐in‐Aid for Research and Development (PI)
FY2014 - FY2016 JSPS Grant-in-Aid for Scientific Research (B), #26282043 (Co)
FY2013 - FY2015 JSPS Grant-in-Aid for Young Scientists (B), #25800257 (PI)
FY2011 FGI Grant-in-aid, Fukada Geological Institute (PI)
FY2009 - FY2010 JSPS Grant-in-Aid for Young Scientists (Start-up), #21840022 (PI)
FY2005 - FY2007 JSPS Grant-in-Aid for JSPS Fellows (DC1), #05J11788 (PI)

Awards

2015 Toray Science Education Prize Encouragement Award

Research Topics

Friction of granular matter, rocks and faults
Friction of granular matter is important in analyzing various phenomena in geosciences such as landslides, debris flows, crater formation and earthquake. How friction depends on the sliding velocity is an important problem because it determines the stability of mountains, hills and faults; for this reason, it has been investigated in various research fields. In geoscience, the rate- and state-dependent friction law is established based on experiments conducted at very slow shear rates, at which the friction coefficient generally exhibits negative shear-rate dependence. In statistical physics, another empirical law holds for much faster deformation (such as flow on an inclined plane), for which the friction coefficient exhibits positive shear-rate dependence. However, it remains unknown how these two distinct laws are connected (or not connected). We experimentally show that the crossover from negative to positive shear-rate dependence occurs at a characteristic shear rate, relating to competition between two different physical processes.

Friction experiment of granular layer.

Publications

Papers (peer-reviewed)

  • Kuwano, O., S. Yoshida, M. Nakatani, and M. Uyeshima (2015), Origin of transient self-potential signals associated with very long period seismic pulses observed during the 2000 activity of Miyakejima volcano, J. Geophys. Res. Solid Earth, 120, doi: 10.1002/2014JB011740.
  • Kuwano, O., R. Ando, and T. Hatano (2013), Granular Friction in a Wide Range of Shear Rates, AIP Conf. Proc. 1542, 32-37, doi:10.1063/1.4811863.
  • Kuwano, O., R. Ando, and T. Hatano (2013), Crossover from negative to positive shear rate dependence in granular friction, Geophys. Res. Lett., 40, 1295-1299, doi:10.1002/grl.50311.
  • Hatano, T., and O. Kuwano (2013), Origin of the velocity-strengthening nature of granular friction, Pure and Applied Geophysics, doi:10.1007/s00024-011-0409-9.
  • Kuwano, O., and S. Yoshida (2012), Changes in electrokinetic coupling coefficients of granite under triaxial deformation, International Journal of Geophysics, Vol.2012, 290915.
  • Kuwano, O., and T. Hatano (2011), Flash weakening is limited by granular dynamics, Geophys. Res. Lett., 38, L17305, doi:10.1029/2011GL048530.
  • Kuwano, O., M. Nakatani, and S. Yoshida (2007), Reply to comment by A. Revil on 'Effect of the flow state on streaming current', Geophys. Res. Lett., 34, L09312, doi:10.1029/2006GL029136.
  • Kuwano, O., M. Nakatani, and S. Yoshida (2006), Effect of the flow state on streaming current, Geophys. Res. Lett., 33, L21309, doi:10.1029/2006GL027712.