California Aftershock Model Uncertainties

California aftershock model uncertainties.

California aftershock hazard forecasts.

1) quantile points at the selected times, S, corresponding to the expected probability and ± 1 SD (Table 1). The standard error in P rapidly decreases with increasing time after the mainshock due to the inclusion of current data. For example, at S = 1 day after the mainshock, the ± 1 SD range about the generic 1-day interval probability (0.052) is 0.034 to 0.075 (Table 1). Rydelek suggests esti...

Propagation of Coulomb stress uncertainties in physics-based aftershock models

Stress transfer between earthquakes is recognized as a fundamental mechanism governing aftershock sequences. A common approach to relate stress changes to seismicity rate changes is the rate-and-state constitutive law developed by Dieterich: these elements are the foundation of Coulomb-rate-and-state (CRS) models. Despite the successes of Coulomb hypothesis and of the rate-and-state formulation...

Static Stress Drop in the 1994 Northridge , California , Aftershock Sequence

We use time-domain pulse widths to estimate static stress drops for 279 M L 2.5 to 4.0 aftershocks of the 17 January 1994, M w 6.7 Northridge, California, earthquake. The stress drops obtained range from 0.02 to 40 bars, with a log average of 0.75 bar. Error bars computed for our estimates are typically a factor of 5, indicating that the three order of magnitude scatter in stress drops is not s...

X - 2 WERNER AND SORNETTE : MAGNITUDE UNCERTAINTIES AND FORECASTS the Epidemic Type Aftershock Sequence

The Collaboratory for the Study of Earthquake Predictability (CSEP) aims to prospectively test time-dependent earthquake probability forecasts on their consistency with observations. To compete, time-dependent seismicity models are calibrated on earthquake catalog data. But catalogs contain much observational uncertainty. We study the impact of magnitude uncertainties on rate estimates in clust...