The dynamics of the stress state in Southern California based on the geomechanical model and current seismicity: Short term earthquake prediction

Abstract

The three-dimensional geomechanical model of Southern California was developed including a mountain relief, fault tectonics and internal border characteristics such as the roof of the consolidated crust and Moho surface. During the last six years on the basis of the developed geomechanical model and current seismicity is realized an approbation of technology for the estimation of possible future seismicity on a two weeks interval. All four strongest events with ∼ 5.5 − 7.2 occurred in South California during the analyzed period were prefaced by the stress anomalies in peculiar advance time of weeks-months. Inside the stress state background level investigation it was identified the feature of the large-scale interaction between two seismically active tectonic provinces of Southern California. KEYWORDS:Geomechanical model; stress-strain state; earthquakes.Citation: Bondur, V. G., I. A. Garagash, and M. B. Gokhberg (2017), The dynamics of the stress state in Southern California based on the geomechanical model and current seismicity: Short term earthquake prediction, Russ.

Revealing Short-Term Precursors of the Strong M > 7 Earthquakes in Southern California From the Simulated Stress–Strain State Patterns Exploiting Geomechanical Model and Seismic Catalog Data

“…The results presented in this study have been obtained with a geomechanical modeling-based monitoring technique (Bondur et al, 2010;Bondur et al, 2016;Bondur et al, 2017;Bondur et al, 2020), allowing one to image and trace the SS evolution over the Southern California region during the period from 2009 to 2019, with the identification of SS precursor patterns preceding strong (M > 7) seismic events. At the core of this technique lies a threedimensional (3D) geomechanical model simulating the crustal rock deformation within the latitudes between 31 and 36°N and longitudes between 114 and 121.2°W assuming the Mohr-Coulomb yield criterion.…”

“…To monitor the SS dynamics in relation to strong earthquakes in Southern California, back in 2009 we launched a numerical simulation study, employing both geomechanical modeling and actual seismological data (Bondur et al, 2010;Bondur et al, 2016;Bondur et al, 2017;Bondur et al, 2020). In our model, every new earthquake is treated as a new crustal defect, causing the stress-state redistribution and variation over time.…”

Early Manifestations of Short-Term Precursors in Stress-Strain State Dynamics of Southern California

“…The geomechanical model of Southern California developed in 2010;2017) allows for monitoring the stress-strain state (SSS) dynamics based on local current seismicity data (USGS catalog https://earthquake.usgs.gov/data/comcat/) and revealing the short-term precursors of the strong earthquakes (Bondur et al, 2020a;2020c;2021). Most informative deformational variations are observed in the increments of shear deformation (SD) and from parameter D reflecting the proximity of rocks to the ultimate strength, which are calculated in the model with a time step of 0.5 months.…”