基于加卸载响应比的前震识别方法应用及实例检验
李泽平1,2,余怀忠3,杨志高3,张靖雪3

(1.中国地震局地震研究所,湖北 武汉 430071; 2.湖北省地震局,湖北 武汉 430071; 3.中国地震台网中心,北京 100045)

加卸载响应比; 固体潮; 前震; 震后趋势分析; 地震预测

Test and Application of the Foreshock Identification Method Based on the Load/Unload Response Ratio
LI Zeping1,2,YU Huaizhong3,YANG Zhigao3,ZHANG Jingxue3

(1.Institute of Seismology,China Earthquake Administration,Wuhan 430071,Hubei,China)(2.Hubei Earthquake Agency,Wuhan 430071,Hubei,China)(3.China Earthquake Networks Center,Beijing 100045,China)

Load/Unload Response Ratio; foreshock; earth tide; analysis of the post-earthquake risk tend; earthquake prediction

DOI: 10.20015/j.cnki.ISSN1000-0666.2025.0023

备注

为了验证改进的加卸载响应比方法在前震识别中的有效性,对基于该方法开发的前震识别系统自动产出的地震预测结果进行整理分析。统计2021年10月—2024年4月中国大陆西部地区190次4级以上非前震地震,发现处于固体潮加载阶段的地震占比为35.8%,卸载阶段占比更大,为64.2%。统计了2021年5月21日云南漾濞6.4级地震的4次前震、2021年12月24日老挝6.0级地震的2次前震和2022年6月10日四川马尔康6.0级地震的3次前震的固体潮的加卸载状态,发现所有前震均在固体潮加载阶段发生。结合前震判定和震后趋势分析的“交通灯”模型,对2024年4月10日新疆拜城5.6级震群、1月23日新疆乌什7.1级余震序列以及4月3日台湾花莲7.3级地震的2次强余震(6.3级、6.2级)的加卸载判定结果进行研究,并对原震区后续强震危险性进行了分析,结果显示加载地震后发生更强地震的情况与后续实际地震发震情况较为符合。通过R值评分和概率增益分析可知,在95%置信度下,R>R0、概率增益Gain>1,表示基于LURR的前震识别方法能够通过显著性检验,并且有较好的预测效能,说明该方法适用于中国大陆西部地区震后趋势的实时判定。
We sorted out and analyzed the forecasting results produced by the foreshock identification system developed based on the improved Load/Unload Response Ratio(LURR)method to verify the effectiveness of this method in foreshock identification.The western region of Chinese mainland was selected as the study area.In this region,64.2% of all 190 non-foreshocks(M>4.0)occurred during the unloading process,while the remaining events triggered during the loading process.The results indicated that non-foreshocks were more likely to occur during the unloading process.All the 4 foreshocks of the Yangbi MS6.4 earthquake in Yunnan on May 21,2021,2 foreshocks of the Laos MS6.0 earthquake on December 24,2021,and 3 foreshocks of the Maerkang MS6.0 earthquake in Sichuan on June 10,2022 were triggered during the loading process.Further,by using the “traffic light” model for foreshock identification and seismic risk analysis,we categorized the loading/unloading states and researched the risk of strong earthquakes in seismogenic areas for the Baicheng MS5.6 earthquake sequence on April 10,2024,the Wushi MS7.1 sequence on January 23,2024 in Xinjiang Uygur Autonomous Region,and two strong aftershocks(MS6.3,MS6.2)of the Hualien MS7.3 earthquake sequence on April 3,2023 in Chinese Taiwan.The results showed that the occurrence of stronger earthquakes after loading earthquake was consistent with the actual earthquake situation.Analyzing with R-value and probability gain,we can see that R-value is greater than R0-value with 95% confidence and the probability gain is greater than 1,this indicates that the foreshock identification method based on the Load/Unload Response Ratio(LURR)can pass the significance test,and the prediction effect is good.This method is suitable for real-time assessment of the seismic risk trend in the western region of the Chinese mainland.