九寨沟7.0级地震前电离层TEC异常分析

Analysis of ionospheric TEC anomalies before the Jiuzhaigou Ms 7.0 earthquake

以2017-08-08四川省九寨沟Ms7.0地震为背景,利用IGS提供的全球电离层格网数据,采用滑动四分位距法对震中所在网格的四个格网点进行TEC异常分析。发现震前13天,震前4天和地震当天分别出现了不同程度的电离层异常。结合同时段的太阳地磁活动情况,可以确定地震当天的电离层异常与此次地震的相关性。进一步分析电离层异常的空间分布后,确认震前13天的电离层异常可作为九寨沟地震的前兆,而震前4天出现的电离层异常是由地磁剧烈活动引起的。

Based on the Ms 7.0 earthquake in Jiuzhaigou,Sichuan Province on August 8,2017,and with the global ionospheric grid data provided by IGS,the sliding quartile method is used to analyze the four grid points of the grid in the epicenter Perform TEC anomaly analysis.Thirteen days before the earthquake,four days before the earthquake and the earthquake on the same day,respectively,have the varying degrees of ionospheric anomalies.Combined with the days of the sun geomagnetic activity,this paper can determine the correlation between the ionosphere anomaly of earthquake day and this earthquake.After the further analysis of ionospheric anomalies’spatial distribution,it is confirmed that the ionospheric anomaly that occurred 13 days before the earthquake can be used as a precursor to the Jiuzhaigou earthquake.The ionospheric anomaly that occurred four days before the earthquake was caused by geomagnetic intense activity.