晋冀蒙交界地区地震活动性增强分析和预测规则的优化  

Seismicity enhancement analysis and optimization of the prediction rule in the juncture area of Shanxi,Hebei,and Inner Mongolia

作　　者：张帆[1] 韩晓明[1] 李娟[1] 裴东洋 ZHANG Fan;HAN Xiaoming;LI Juan;PEI Dongyang(Earthquake Agency of Inner Mongolia Autonomous Region,Hohhot 010051,Inner Mongolia,China)

机构地区：[1]内蒙古自治区地震局,内蒙古呼和浩特010051

出　　处：《地震工程学报》2022年第6期1422-1428,共7页China Earthquake Engineering Journal

基　　金：中国地震局地震科技星火计划(XH20014);中国地震局震情跟踪定向任务(2020020103)。

摘　　要：晋冀蒙交界地区处于华北地块、鄂尔多斯地块和燕山地块交界处,其地震活动受到构造应力场变化的影响,和未来中强地震有一定关联性。2019年以来,晋冀蒙交界地区出现M3.0以上地震显著增强现象,为了评估此区域地震活动起伏的震兆意义,构建有效的预测方法,文章将增强区域作为地震频次的窗口,选取M3.0以上地震年滑动频次为预测指标。通过回溯历次5级以上地震前的地震活动情况,确定最优预测规则。经过在预测规则参数空间扫描,以R值作为目标函数,最终确定的预测窗长和阈值为2年和14次,在此规则下地震频次预测指标有较好的预测效果和较高信度。The juncture of Shanxi,Hebei,and Inner Mongolia is located at the border area of the North China Block,Ordos Block,and Yanshan Block.The seismicity of this area,which is affected by the change in the tectonic stress,is related to future moderately strong earthquakes.The earthquake prediction index extracted from the observation data is a parameter with a certain physical significance,which has some degree of abnormal changes before an earthquake.The construction of the earthquake prediction index system is one of the most effective prediction methods in the empirical prediction stage.The earthquake frequency,which reflects the changes in the seismicity level and stress level,is a commonly used earthquake prediction index.Since 2019,there has been a significant enhancement of M>3.0 earthquakes in the border area of Shanxi,Hebei,and Inner Mongolia.To evaluate the earthquake precursor significance of the seismicity in this area and build an effective prediction method,the enhanced area was selected as the window of earthquake frequency,and the annual moving frequency of M>3.0 earthquakes was taken as the prediction index.The optimal prediction rule was determined by tracing back the seismicity before previous M>5.0 earthquakes.Through a spatial scanning of the parameters of the prediction rule and taking the R value as the objective function,the prediction window length and threshold were finally determined to be 2 years and 14 times,respectively.The earthquake frequency prediction index for the proposed rule has a good prediction effect and high reliability.

关 键 词：地震活动增强 预测效能 晋冀蒙交界 ROC 

分 类 号：P315.5[天文地球—地震学]