Analytical prediction of seismicity rate due to tides and other oscillating stresses

Abstract

Oscillatory stresses are ubiquitous on Earth and other solid‐surface bodies. Tides and seasonal signals perpetually stress faults in the crust. Relating seismicity to these stresses offers fundamental insight into earthquake triggering. We present a simple model that describes seismicity rate due to perpetual oscillatory stresses. The model applies to large‐amplitude, nonharmonic, and quasiperiodic stressing. However, it is not valid for periods similar to the characteristic time ta. We show that seismicity rate from short‐period stressing scales with the stress amplitude, but for long periods with the stressing rate. Further, that background seismicity rate r is equal to the average seismicity rate during short‐period stressing. We suggest that Aσ₀ may be underestimated if stresses are approximated by a single harmonic function. We revisit Manga et al. (2019, https://doi.org/10.1029/2019GL082892), which analyzed the tidal triggering of marsquakes and provide a rescaling of their seismicity rate response that offers a self‐consistent comparison of different hydraulic conditions.