Dynamic simulation of interactions between major earthquakes on the Xianshuihe fault zone

Abstract

The authors firstly evaluate the strain accumulation rate of the Xianshuihe fault zone based on earthquake activity. We calculated the stress and seismic moment accumulation rate for each subsection of the Xianshuihe fault zone based on the distribution of geological slip rate and GPS survey results. According to the results, we get the recurrence intervals of characterized earthquakes on each subsection respectively. A three-dimensional finite element model for western Sichuan is constructed to discuss the earthquakes triggering among major earthquakes ({ntM}>6.7) that occurred along the Xianshuihe fault zone since 1893. The calculated Coulomb failure stress changes (ACFS) show that 5 of the 6 earthquakes with Ms>6.7 were triggered by positive ACFS. The interactions between major earthquakes not only influence recurrence intervals of characterized earthquakes on each subsection, but also change recurrence behavior of major earthquakes along the whole fault zone.