Evaluation of Seismicity Triggering: Insights from the Coulomb Static Stress Changes after the 30 August 1968 Dasht-e-Bayaz Earthquake (Mw = 7.1), Eastern Iran

Abstract

In this research the Coulomb stress changes due to earthquake sequence that began in the 1936 to 1997 earthquakes in Eastern Iran and their triggering effect on the rupturing of adjacent faults were investigated. Obtained results revealed a well triggering relation between main shocks and later events on the Dasht-e-Bayaz and Abiz faults, respectively. The calculated stress maps indicate that positive and negative zones of Coulomb stress changes with increasing lobes of 0.1‒1 bar are found in the off-faults tips, located at rupture terminates while the decreasing Coulomb stress lobes lie in the high angle relative to the rupture plane or relieve stress along the ruptures. Cross sections drawn respect to the source and received faults confirm the results. Also, the stress perturbations resulted from successive earthquakes and the spatial patterns of the following earthquake distribution have a good consistency. This correlation shows that the population of secondary faults and subsequent earthquakes can be encouraged in the future by coseismic Coulomb stress changes due to mainshock and background loading.