2010 Fiscal Year Final Research Report

What determines the critical slip distance of the fault?

Research Project

Project/Area Number	21840022
Research Category	Grant-in-Aid for Research Activity Start-up
Allocation Type	Single-year Grants
Research Field	Solid earth and planetary physics
Research Institution	The University of Tokyo
Principal Investigator	KUWANO Osamu The University of Tokyo, 地震研究所, 特任研究員 (30511969)
Project Period (FY)	2009 – 2010
Keywords	粉体 / 摩擦 / 断層 / 地震 / 室内実験
Research Abstract	The frictional properties of granular matter are important for analyzing various phenomena in geosciences. Here we conduct an experiment on the deformation-rate dependence of the kinetic friction coefficient, which determines the stability of granular flow. By changing the deformation rate over four orders of magnitude, we find the characteristic rate at which the least friction is realized. The result does not depend on the shape of the grains. The least friction is explained in terms of the competition between two very different physical processes, namely frictional healing and anelasticity. We determine the expression of the characteristic rate.