Illuminating the physics of dynamic friction through laboratory earthquakes on thrust faults
Yuval Tal, Vito Rubino, Ares J. Rosakis, & Nadia LapustaPublished September 1, 2020, SCEC Contribution #10938
Large, destructive earthquakes often propagate along thrust faults including megathrusts. The asymmetric interaction of thrust earthquake ruptures with the free surface leads to sudden varia- tions in fault-normal stress, which affect fault friction. Here, we present full-field experimental measurements of displacements, particle velocities, and stresses that characterize the rupture inter- action with the free surface, including the large normal stress reduc- tions. We take advantage of these measurements to investigate the dependence of dynamic friction on transient changes in normal stress, demonstrate that the shear frictional resistance exhibits a significant lag in response to such normal stress variations, and identify a predictive frictional formulation that captures this effect. Properly accounting for this delay is important for simulations of fault slip, ground motion, and associated tsunami excitation.
Citation
Tal, Y., Rubino, V., Rosakis, A. J., & Lapusta, N. (2020). Illuminating the physics of dynamic friction through laboratory earthquakes on thrust faults. Proceedings of the National Academy of Sciences, 117(35), 21095-21100. doi: 10.1073/pnas.2004590117.
