Linking Dynamic Rupture and Frictional Sliding in Earthquakes: Insights from High-Speed Experiments

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Presenter

Xiaofeng Chen, Ph.D.
Assistant Professor
Boone Pickens School of Geology
Oklahoma State University

Description

Earthquakes initiate with dynamic rupture and transition into frictional sliding, yet the coupling between these processes remains poorly understood. This study investigates transient fault behavior during this transition using high-speed sliding and stick-slip experiments with a high-acceleration double-direct shear apparatus. Results show dominant velocity-weakening behavior during fault acceleration and deceleration, with partial agreement with flash-heating models but systematic deviations during acceleration linked to dynamic rupture effects. Thermal and microstructural observations indicate that high-speed sliding is governed by frictional energy dissipation. Complementary experiments further reveal significant coseismic shear stress recovery and lithology-dependent restrengthening, with granite exhibiting consistent recovery (50–80%) and quartzite showing more variable behavior (5–70%). These findings demonstrate that fault composition and high acceleration critically influence transient weakening and strengthening, highlighting the importance of rupture–friction coupling in controlling earthquake mechanics and improving physics-based rupture models.