Earthquake model shakes things up to uncover relationships between seismic parameters

Correlations between earthquake parameters are difficult to study because of the need for observational data. However, evidence from Iran, California and the Pannonian Basin suggest a universal relationship between the stress conditions of a seismic area, the magnitude of an earthquake, and its connectivity with other earthquakes. Using a dynamic tectonic plate model, Perez-Oregon et al. aimed to verify this universality.

The authors used the Olami-Feder-Christensen spring-block model, which treats tectonic plates as a system of blocks connected by springs to one another and to a slow moving upper plate. Earthquakes are represented by forces applied to individual blocks, changing the entire system. By varying the input parameters in this simulation, different types of seismic events can be synthesized and compared.

With this technique, the group was able to confirm a relationship between the seismological and topological features of an earthquake. Specifically, they found the maximum characteristic earthquake of an area follows an inverse relationship with the age of its tectonic plates, which also affects the rate of seismic events. Additionally, the latter quantity is constant with respect to magnitude and connectivity degree within a realistic range of seismicity variation.

“The analysis of the topological properties of earthquake sequences is still at its early stage,” said author Luciano Telesca. “The relationship between seismic parameters and topological parameters could prompt the investigation of seismic sequences from a new perspective.”

Source: “Visibility graph analysis of synthetic earthquakes generated by the Olami-Feder-Christensen spring-block model,” by Jennifer Perez-Oregon, Michele Lovallo, and Luciano Telesca, Chaos (2020). The article can be accessed at https://doi.org/10.1063/5.0007480 .