Comment on nhess-2022-46

Abstract

This study identifies fault pairs with potential for simultaneous rupture in a coseismic period based on a physics-based model, and proposes a set of formulas to evaluate their recurrence intervals and uncertainties. To assess the potential for a multiple-fault rupture, we calculated the probability of stress triggering between active faults. We assumed that a multiple-fault rupture would occur if two faults could trigger each other by enhancing the plane with thresholds of a stress increase and the distance between the faults. To estimate the recurrence intervals for multiple-fault ruptures, we implemented a statistics-based model in which the slip rate could be partitioned based on the earthquake magnitudes of the individual fault and multiple-fault ruptures. Due to a larger characteristic magnitude and a larger displacement of the multiple-fault rupture, its recurrence interval could be longer. Therefore, application of the multiple-fault rupture could lead to an increase in seismic hazard in a long return period, which would be crucial for the safety evaluation of infrastructures, such as nuclear power plants and dams.