A Model of Fault Gouge with Dissipative Rotational Interactions

Abstract

Gouge--microstructure near faults--the existence of which is accepted as a compromise between data from laboratory experiments and from earthquakes is modelled under the following assumptions : An internal energy is assumed to be a function of strains referred on the particle frame and rotation differences between rotations referred on the absolute frame and ones on the particle frame. Simultaneously, a dissipation law is formulated from the law of entropy production. From characteristic equations, three branches of solutions are derived : (i) Non-attenuative and non-dispersive longitudinal waves (ii) Two types of transversal waves-- A. weakly dispersive and attenuative waves which have a limit to those of perfect elasticity B. non-causal and dissipative waves which have a limit to those of pure dissipation Pre-seismic or post-seismic time-dependent deformations and coseismic quasi-elastic deformations are discussed from the proposed model.