Simon published a paper in Journal of Geophysical Research, Solid Earth entitled “Preparatory Slip in Laboratory Faults: Effects of Roughness and Load Point Velocity”. Simon’s paper presents outcomes of displacement-rate controlled friction experiments on roughened sawcut granite samples with different surface roughness at a confining pressure of 35 MPa. We measured how forces accumulated by friction were released by measuring stresses and displacements at the block edges with local deformation sensors and recording very small earthquakes that occur during sliding along the saw-cut faults. We found that our faults tend to release all the accumulated energy very abruptly, after a very small amount of slip and regardless of the applied load point velocity. The processes leading to failure on a rough fault were, however, much more complex and involved a large amount of slip and numerous small earthquakes that are heterogeneously distributed in space and time.
Guérin-Marthe, S., G. Kwiatek, L. Wang, A. Bonnelye, P. Martínez-Garzón, and G. Dresen (2023). Preparatory Slip in Laboratory Faults: Effects of Roughness and Load Point Velocity, Journal of Geophysical Research: Solid Earth 128, no. 4, e2022JB025511, DOI: 10.1029/2022JB025511. [ Article Page ] [ Download open-access article ] [ Link to data publication ]