Microscale Yielding as Mechanism for Low-frequency Intrinsic Seismic Wave Attenuation

We revisit the idea of microscale yielding being responsible for attenuation of small amplitude waves in a wide frequency range. We consider microscopic rate-independent irreversible deformation around cavities causing local stress amplification in pre-stressed porous media as a mechanism responsible for frequency independent attenuation. Following the effective media approach, we consider low porosity material containing non-interacting isolated spherical pores under cyclic loading by isotropic stress field imitating passage of a wave, and evaluate resulting dissipation in terms of quality factor Q. Assuming initial local microscopic stress state around the cavity at the yield, we show that even for small seismic strains attenuation can be high and independent of both frequency and strain amplitude.