基于PI方法的华北2019年以来3次M_(S)≥5.0地震回溯性预测研究  

Retrospective Study on the Forecasting of the Three M_(S)≥50 Earthquakes Since 2019 in North China Based on PI Method

作　　者：宋程 张永仙[2] 夏彩韵 毕金孟 张小涛[4] 吴永加[4] 徐小远[1] SONG Cheng;ZHANG Yong-xian;XIA Cai-yun;BI Jin-meng;ZHANG Xiao-tao;WU Yong-jia;XU Xiao-yuan(Tianjin Earthquake Agency,Tianjin 300201,China;Institute of Earthquake Forecasting,China Earthquake Administration,Beijing 100036,China;Liaoning Earthquake Agency,Shenyang 110031,China;China Earthquake Networks Center,Beijing 100045,China)

机构地区：[1]天津市地震局,天津300201 [2]中国地震局地震预测研究所,北京100036 [3]辽宁省地震局,沈阳110031 [4]中国地震台网中心,北京100045

出　　处：《地震》2024年第2期120-134,共15页Earthquake

基　　金：天津市自然科学基金青年项目(22JCQNJC01070);天津市地震局重点科研项目(Zd202402,Zd202304);地震科技星火计划项目(XH24005YA);中国地震局震情跟踪定向工作任务(2024010111)。

摘　　要：本文应用图像信息(PI)方法对2023年山东平原M_(S)5.5地震、2021年江苏大丰海域M_(S)5.0地震和2020年河北古冶M_(S)5.1地震进行了回溯性预测研究。以华北局部(32°N~42°N,114°E~122°E)为研究区域,在网格尺度分别为0.5°×0.5°和1.0°×1.0°且预测窗长为5 a的两组参数模型下,获取2019—2027年逐年滑动的预测窗热点演化图像。结果显示,当网格尺度为1.0°×1.0°时,PI热点效果优于0.5°×0.5°网格,且对平原地震和大丰海域地震的发震位置指示作用较好。当时间窗长和归一化阈值绝对值同时增大,个别窗口存在古冶地震的有效热点,但未找到热点能同时覆盖3个地震震中所在网格的参数模型。不同参数模型下的PI热点显示,未来3~4 a郯庐断裂带渤海段存在发生M_(S)≥5.0地震的风险。本文研究结果对于华北局部地区M_(S)≥5.0地震危险性分析具有一定的参考意义。In this paper,the local area of North China(32°N~42°N,114°E~122°E)was chosen as studied region.Regarding the 2023 Shandong Pingyuan M_(S)5.5 earthquake,2021 Dafeng sea area M_(S)5.0 earthquake and 2020 Hebei Guye M_(S)5.1 earthquake as the target earthquakes,the Pattern Informatics(PI)method was applied to the retrospective research on the forecasting seismic activity risk of the three earthquakes.With parameters of forecasting window length 5 years and grid size 0.5°×0.5°/1.0°×1.0°,the period from 2019 to 2027 of successive hotspot forecasting window images sliding year by year were obtained.The results show that PI hotspot effect with the grid size 1.0°×1.0°is better than 0.5°×0.5°.And it has a good indication effect on the location of Pingyuan and Dafeng sea area earthquakes.When the time window length and the absolute value of the normalization threshold increasing,only a few windows have effective hotspots for the Guye earthquake.But no parameter model that can simultaneously cover the epicenter grid of the three earthquakes has been found.The PI hotspots under different parameter models indicate,there is a risk of M_(S)≥5.0 earthquake in the Bohai Rim region of the Tan-Lu fault zone in the following 3~4 years.The results of this paper can provide certain reference significance about seismic hazard analysis of M_(S)≥5.0 earthquake for local area of North China.

关 键 词：2023年平原M_(S)5.5地震 2021年大丰海域MS5.0地震 2020年古冶MS5.1地震 图像信息方法 热点迁移 

分 类 号：P315.7[天文地球—地震学]