Poster #082, Seismology
Weak Off-fault Structures Revealed by Microseismicity along Xiaojiang Fault Zone (China) and Their Implications for Seismic Hazard Assessment
Poster Image:
Poster Presentation
2020 SCEC Annual Meeting, Poster #082, SCEC Contribution #10522 VIEW PDF
icroseismicity reveals widespread off-fault structures along XJF. Micro-seismicity near the main fault are only concentrated near its junction with off-fault structure. To investigate the difference in stress state and slip behavior between the main fault and off-fault structures, we further map the b-value and identify repeating earthquakes. These results show that the off-fault structures are characterized by high level of microseismicity and high b-value, and are able to generate repeaters. Because most micro-seismicity occurred on off-fault structures, the associated b-values is not necessarily related to the stress status of the main fault. To assess the magnitude potential, we take b-value of on fault clusters as a reference, and find that the relative b-value on XJF is lower than its northern counterparts, i.e. the Anninghe-Zemuhe Fault (AZF) and Xianshuihe Fault (XSHF). This agrees with the relative moment deficit values of these three faults estimated by geodetic method: M7.2, M7.4, and M7.6 for XSHF, AZH, and XJF, respectively. In time predictability, a recurrence interval of 300 year for M7 event is provided by paleoseismic studies. These evidences infer the XJF has a high potential for a M>7 earthquake in the near future.
SHOW MORE
SHOW MORE