Physics-Based Simulation of Spatiotemporal Patterns of Earthquakes in the Corinth Gulf, Greece, Fault System Rodolfo Console *1,2 , Roberto Carluccio 2 , Maura Murru 2 , Eleftheria Papadimitriou 3 , and Vassilis Karakostas 3 ABSTRACT A physics-based earthquake simulation algorithm for modeling the long-term spatiotem- poral process of strong (M ≥ 6.0) earthquakes in Corinth Gulf area, Greece, is employed and its performance is explored. The underlying physical model includes the rate- and state-dependent frictional formulation, along with the slow tectonic loading and coseismic static stress transfer. The study area constitutes a rapidly extending rift about 100 km long, where the deformation is taken up by eight major fault segments aligned along its southern coastline, and which is associated with several strong (M ≥ 6.0) earthquakes in the last three centuries, since when the historical earthquake catalog is complete. The recurrence time of these earthquakes and their spatial relation are studied, and the simulator results reveal spatiotemporal properties of the regional seismicity such as pseudoperiodicity as well as multisegment ruptures of strong earthquakes. As the simu- lator algorithm allows the display of the stress pattern on all the single elements of the fault, we are focusing on the time evolution of the stress level before, during, and after these earthquakes occur. In this respect, the spatiotemporal variation of the stress and its heterogeneity appear to be correlated with the process of preparation of strong earth- quakes in a quantitative way. KEY POINTS • We simulated a long stress and seismicity history for the main fault segments of the Corinth Gulf. • Our attention was focused on the time evolution of the stress before, during, and after strong earthquakes. • The results provide inferences on the spatiotemporal properties of seismic activity in the study area. Supplemental Material INTRODUCTION Earthquake simulators, becoming powerful and widely accepted as promising tools for a better understanding of the physical earthquake process, were initially based on the elastic rebound theory for earthquake generation, introduced by Reid (1910) in his seminal study on the 1906 San Francisco earthquake. Starting from the pioneering work of Burridge and Knopoff (1967), the earthquake process has been simulated by a slider-block model in which each spatially coarse grained site on a fault is represented by a block sliding on a frictional sur- face. Physically, the blocks are considered to represent the locked patches, or asperities, on the fault surface. Even though the original slider-block model specified massive inertial blocks, recent models have rather focused on the stochastic cel- lular automaton type (Rundle and Jackson, 1977; Rundle and Brown, 1991; Rundle et al., 2002). An alternative physically based, class of simulator models incorporates dynamic stress transfer and can simulate multiple earthquake cycles (see Erickson et al., 2020, and references therein). In the following, we give a review of the most known and widely accepted earthquake simulator codes (focusing on the cellular automaton type) introduced during the last two dec- ades, along with a brief discussion of their main features. In this review, we try to follow a sort of chronological order according to the time of their initial formulation. However, the simulator codes can be better distinguished on the basis of the dominant physics included in their algorithms. In fact, 1. Center of Integrated Geomorphology for the Mediterranean Area, Potenza, Italy, https://orcid.org/0000-0001-5128-0637 (RCo); 2. Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy, https://orcid.org/0000-0003-4344-0965 (RCa); https://orcid.org/0000-0002-7385-394X (MM); 3. Geophysics Department, Aristotle University of Thessaloniki, Thessaloniki, Greece, https://orcid.org/0000- 0003-3574-2787 (EP); https://orcid.org/0000-0003-4462-7094 (VK) *Corresponding author: rodolfo.console@ingv.it Cite this article as Console, R., R. Carluccio, M. Murru, E. Papadimitriou, and V. Karakostas (2021). Physics-Based Simulation of Spatiotemporal Patterns of Earthquakes in the Corinth Gulf, Greece, Fault System, Bull. Seismol. Soc. Am. 112, 98–117, doi: 10.1785/0120210038 © Seismological Society of America 98 • Bulletin of the Seismological Society of America www.bssaonline.org Volume 112 Number 1 February 2022 Downloaded from http://pubs.geoscienceworld.org/ssa/bssa/article-pdf/112/1/98/5518841/bssa-2021038.1.pdf by Aristotle Univ of Thessaloniki Central Library, 10336 on 02 February 2022