Effect of Wenchuan earthquake on probabilities of earthquake occurrence of Lushan and surrounding faults

Static stress changes have been proposed to explain variations of seismicity rates, off-fault aftershocks and probability changes for the occurrence of impending earthquakes. The occurrence of Lushan M_S7.0 earthquake re-arouses the hot discussion about the Wenchuan M_S8.0 earthquake. Based on the rate-and-state dependent frictional law, combined with the seismicity analysis before and after Wenchuan earthquake, we have quantitatively calculated the probability of earthquake occurrences in Ya'an area, and explained the probable causes of Lushan M_S7.0 earthquake. In addition, we have also computed the earthquake probabilities of Xianshuihe and Xiongpo faults, where the Coulomb stress also increased after Wenchuan earthquake. The results are in accordance with the earthquake catalog of the China Earthquake Networks Center. No earthquake of M>6.0 happened on the Xianshuihe fault since the Wenchuan earthquake five years ago, but the probability of M>6.0 earthquake is about 60% at present. There is no earthquake of M>4.0 occurred on Xiongpo fault in the past five years, but the probabilities of earthquake occurrence of M>4.0 is nearly 90% after the Lushan earthquake. Therefore, we propose that Xianshuihe area will become the key area to monitoring M>6.0 earthquakes, and destructive earthquakes are still likely to occur in Xiongpo area.