The effect of temperature on the nonlinear elasticity of a fault rock in dynamic acoustoelastic testing (DAET) experiments

Summary Dynamic nonlinear elasticity in rocks may play an important role earth processes, such as earthquake nucleation. In order to understand how occurs within the shallow crust, experiments are required that simulate situ conditions of intact crustal rocks. Additionally, exploring behaviour response changes external parameters (e.g., temperature and wave frequency) acts a means further illuminate complex mechanisms which give rise this study, we perform dynamic acoustoelastic testing (DAET) on cataclasite from damage zone Alpine Fault, New Zealand. By performing pump-probe DAET inside temperature-controlled chamber, able investigate rich variety function temperature. We find magnitude averaging softening, cubic nonlinearity, hysteresis tend increase increases 20 110○C. contrast, quadratic nonlinearity decreases with increasing These observations support hypothesis at least two distinct control phenomena Nonlinear show little no dependence frequency over 200-600 Hz pump range, although values parameter α found be nearly orders smaller than those determined using ultrasonic perturbations. analysis different time windows shows surface waves probe sense greater compared direct P-wave due differences polarisation propagation paths. As well providing insight into responsible for rocks, our softening will zones faults. This has potential implications understanding nucleation processes.