强震前地磁总场F_(02)测值的空间相关特征研究  

Spatial Correlation Characteristics of Geomagnetic Total Field before Strong Earthquakes

作　　者：李鸿宇[1] 袁桂平[1] 

机构地区：[1]江苏省地震局,南京210014

出　　处：《地震》2018年第1期157-166,共10页Earthquake

基　　金：中国地震局2017年度震情跟踪定向工作任务(2017010401);江苏省科技支撑--社会发展项目(BE2016804)

摘　　要：收集全国102个地磁台站2008年至2015年数字化地磁资料,运用地磁空间相关法计算每日凌晨02时各台站地磁总场F之间的空间相关系数。在使用相同的异常判别标准的情况下,研究时段的17个中强地震中发现在2009年9月19日陕西宁强5.1级地震,2011年11月1日四川青川5.4级地震,2013年1月23日辽宁灯塔5.1级地震,2013年7月22日甘肃岷县6.6级地震和2013年10月31日吉林前郭5.5级地震前均具有较为明显的空间相关低值异常现象。通过总结5个震例的异常特征,笔者发现其异常形态极其相似,且平均的异常持续时间为20天,而地震就发生在异常开始后3个月内;同时,地震发生在异常集中区中心附近,且这个异常区域大小在500km左右。这一研究结果对于进一步分析地震前地磁空间相关异常特征积累了丰富的资料。We collected digital geomagnetic data of 102 geomagnetic stations across the country from 2008 to 2015, and calculated the space correlation coefficient between the station geomagnetic total field F on local time 02 by the geomagnetic spatial correlation method. According to the same standard of abnormal judgement, we find that the spatial correlation has obvious anomaly low value before 5 of 17 moderate to strong earthquakes in the studied time period, which respectively are Shanxi-Ningqiang MsS. 1 earthquake on September 19, 2009, Sichuan-Qingchuan Ms5.4 earthquake on November 1, 2011, Liaon- ing-Dengta Ms5.1 earthquake on January 23, 2013, Gansu-Minxian Ms6.6 earthquake in July 22th, 2013, Jilin-Qianguo Ms5.5 earthquake on October 31, 2013. By summarizing the anomaly characteristics of the 5 earthquake examples, we found that their abnormal features are very similar, and the duration time is about 20 days, then the earthquakes oc- curred within 3 months after the start of the anomalies. At the same time, the earthquakes occurred near the center of the abnormal clusters, and the size of the anomaly area is about 500 km. Our results accumulate abundant data and material for further analysis of the a- nomaly characteristics of geomagnetic spatial correlation before earthquakes.

关 键 词：地磁总场F 地震前兆 空间相关 

分 类 号：P315.7[天文地球—地震学]