From Events to Subfaults: Earthquake Source Scaling Using Finite-Fault Models
Margarita Solares
University of Oregon
- Date & Time
- Location
- Hybrid - in person and online via MS Teams
- Host
- Tara Nye
- Summary
Establishing scaling laws for large earthquakes remains challenging due to methodological differences in finite-fault models. Here, we investigate how source properties scale at the subfault level—beyond event-averaged parameters—using 264 earthquakes from the global NEIC finite-fault database. Results favor pulse-like ruptures over crack-like behavior, characterized by shorter rise times. At the subfault scale, the commonly assumed relationship that rise time scales with slip (τ ∝ √s), often used in kinematic and semi-stochastic models, is not supported by the observations, while slip rate strongly correlates with slip. These findings have important implications for ground motion, as localized variations in slip and rise time can influence shaking intensity and spatial distribution. Accounting for this variability can improve rupture simulations and advance our understanding of earthquake processes.