Numerical Modeling Of Frictional Melting Dynamics Constrained By Surface Micro-roughness

Abstract

Under high co-seismic slip rates and normal stress, frictional melt may be generated, extensively weakening a fault and rendering classical rate-and-state friction laws ineffective. Pseudotachylytes (solidified frictional melt) created in laboratories and found in natural fault zones thus provide thermal and mechanical information critical to the study of dynamic shear zone processes, including thermal runaway, stress drop, and viscous braking. While existing geochemical and mineralogical evidence has suggested the occurrence of disequilibrium melting during pseudotachylite generation, few studies have leveraged it to resolve the kinematics of co-seismic slip. This study uses a numerical model to constrain the dynamics of frictional melt formation using pseudotachylyte surface micro-roughness inferred to form due to disequilibrium melting. We optimize the kinematic parameters of the Yo↵e source time function using First and foremost, I would like to thank Phil for his guidance, passion, and care over the past two years that have made my path in science much less unforgiving. Began as an intriguing yet nebulous idea, this project has become one of the few works that I am genuinely proud of. It would not be possible without Phil.A special thank you to Suzanne, who kindled my interest in scientific research and revealed to me the wonderful icy world that I will keep exploring for the years to come.Days with Bridie around the lab were never dull. I would also like to thank Joop and Marty for their review. Thank you to the fantastic faculty: Dana for the excellent gateway course that got me in, Tim for the unique Powerpoint aesthetics and Guam, Joop for amusing lectures interspersed with cold callings, Ginny for always being there, Joel for stories of aircraft and music, and everyone who makes it feel like home.