Quasiperiodic Earthquake Events in an Olami-Feder-Christensen Model
Abstract
We simulated an earthquake fault system using a variation of the OFC cellular automata model. The fault is represented by a 2D lattice structure wherein each site holds some amount of stress. Our model increases the stress on the system in a more realistic way and allows multiple sites to fail simultaneously. The model generates data that produces Gutenberg-Ricther scaling, which is consistent with real earth data. Additionally, the model incorporates ``asperity'' sites into the lattice; these asperities have a much higher failure threshold relative to other sites in the lattice. The introduction of asperities to the system generates a characteristic period according to which we observe very large events. These main shocks are preceded by a gradually increasing number of large events (foreshocks) and followed by a gradually decreasing number of large events (aftershocks). By introducing multiple distinct failure thresholds for the asperity sites, we were able to identify characteristic periods related to the respective failure thresholds. In varying these parameters we can control the periodicity of large earthquake events. These results suggest that the spatio-temporal clustering observed in real seismic data is related to the physical structure of the fault system involved.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..MARE67002O