STUDY OF THE INFLUENCE OF STRONG EARTHQUAKE ON THE RECURRENCE BEHAVIOR OF MAJOR EARTHQUAKE ON ACTIVE FAULT-TAKING THE MIDDLE-NORTH SECTION OF XIANSHUIHE FAULT AS AN EXAMPLE |
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| Authors: | HUI Chun PAN Hua XU Jing |
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| Affiliation: | 1.Institute of Geophysics, China Earthquake Administration, Beijing 100081, China;2.The Second Monitoring and Application Center, China Earthquake Administration, Xi'an 710054, China |
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| Abstract: | It is of great significance to determine the factors and causes that affect the recurrence of major earthquakes. This paper introduces the influence of strong earthquake on the recurrence of major earthquakes according to elastic rebound theory, and then proposes to calculate the impact time Δt respectively from the effect of strong earthquakes on the same and surrounding faults on the major earthquake recurrence by using seismic moment release rate method and Coulomb stress change. In this paper, we studied the change amount of major earthquake recurrence by taking four earthquakes with magnitude greater than 6.5 occurring at different fracture sections of the Xianshuhe fault zone as an example, they occurred on Daofu, Changcu, Zhuwo Fault, respectively. We used seismic moment rate method to calculate the impact time Δt of strong earthquake on the recurrence of major earthquakes on the Daofu-Qianning Fault. We further discussed the effect of the Coulomb stress change due to the interaction between faults on the recurrence of subsequent major earthquakes. The co-seismic and post-seismic Coulomb stress changes caused by strong earthquake on the surrounding faults on the Ganzi-Luhuo Fault are calculated. With the fault interaction considered, the importance of the interaction between faults in the middle-north section of the Xianshuihe fault zone to change the recurrence of large earthquakes is retested and evaluated. The results indicate that the two strong earthquakes occurring along Xianshuihe Fault in 1904(M=7.0) and 1981(M=6.9) resulted in a delay of 80 years and 45 years of major earthquake recurrence on the Daofu-Qianning Fault respectively, and the M7.3 earthquake in 1923 and the M6.8 earthquake in 1967 resulted in an advance of 35 years of major earthquake recurrence on the Ganzi-Luhuo Fault. |
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| Keywords: | impact time seismic moment Coulomb stress Xianshuihe Fault |
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