Slip Patterns on Rate-and-State Faults with Heterogeneous Velocity-Weakening and Velocity-Strengthening Friction

Kavya Sudhir, & Nadia Lapusta

Published August 15, 2017, SCEC Contribution #7789, 2017 SCEC Annual Meeting Poster #174

Slip patterns on heterogeneous interfaces is a complex problem with a wide range of applications, including the nucleation of earthquakes in the transition band between the seismogenic zone and deeper, stably creeping regions and/or in rough fault surfaces. We focus on models of rate-and-state faults that mix instability-promoting velocity-weakening (VW) regions and instability-suppressing velocity-strengthening (VS) regions, from simple repeated patterns with well-defined length scales to more realistic, fractal-like distributions. Both slow and rapid slip events could occur in such surfaces, depending on the fractional area, connectivity, and the size of the resulting VW patches with respect to the nucleation size. We aim to understand how local heterogeneities in friction properties translate into large-scale behaviors, both in terms of stability and slip patterns. In part, we focus on models that reproduce repeating earthquake sequences observed on the creeping segment of the San Andreas fault near Parkfield. We explore how complex, fractal-like distributions in friction properties affect the moments, recurrence times, and interaction of thee repeaters, potentially starting to constrain the level of heterogeneity on natural faults.

Citation
Sudhir, K., & Lapusta, N. (2017, 08). Slip Patterns on Rate-and-State Faults with Heterogeneous Velocity-Weakening and Velocity-Strengthening Friction. Poster Presentation at 2017 SCEC Annual Meeting.

Related Projects & Working Groups
Fault and Rupture Mechanics (FARM)