[M-IS09] Interdisciplinary studies on pre-earthquake processes

[MIS09-02] Earthquake forecasting based on b value and background seismicity rate in Yunnan Province, China

*Rui Wang¹, Yuchen Zhang¹, Peng Han¹, Haixia Shi², Miao Miao¹, Jiancang Zhuang³, Ying Chang⁴, Changsheng Jiang⁵, Lingyuan Meng², Danning Li⁶, Lifang Liu⁶, Youjin Su⁶, Zhenguo Zhang¹ (1.Southern University of Science and Technology, Shenzhen, China , 2.China Earthquake Networks Center, Beijing, China, 3.Institute of Statistical Mathematics, Tokyo, Japan, 4.Institute of Mining Engineering, BGRIMM Technology Group, Beijing, China, 5.Institute of Geophysics, China Earthquake Administration, Beijing, China, 6.Earthquake Administration of Yunnan Province, Kunming, China)

Keywords:earthquake forecast, b value, background seismicity rate, Molchan error diagram, Yunnan Province

Characterized by frequent earthquakes and dense population, Yunnan Province, China faces significant seismic hazards and is a hot place for earthquake forecasting research. In the previous study, we evaluated the performance of b value for 5-year seismic forecasting during 2000-2019 and made a forward prediction of M>=5.0 earthquakes in 2020-2024. In this study, with the forecast period having passed, we first revisit the results and assess the forward prediction performance. Then, the background seismicity rate, which may also offer valuable long term forecasting information, is incorporated into earthquake prediction in Yunnan Province. To assess the effectiveness of the prediction, the Molchan Error Diagram (MED), Probability Gain (PG), and Probability Difference (PD) are employed. Using 25 years catalog, the spatial b value and background seismicity rate across five temporal windows are calculated, and 86 M>=5.0 earthquakes as prediction samples are examined. The predictive performance of the background seismicity rate and b value is comprehensively tested and shown to be useful for 5-year forecasting in Yunnan. The performance of the b value exhibits a positive correlation with the predicted earthquake magnitude. The synergistic effect of combining these two predictors is also revealed. Finally, using the threshold corresponding to the maximum PD, we integrate the forecast information of background seismicity rates and the b value. A forward prediction is derived for the period from January 2025 to December 2029. This study can be helpful for disaster preparedness and risk management in Yunnan Province, China.