GPS应变场云图方法识别地震形变场异常初步分析

Preliminary Analysis of GPS Strain Field Cloud Method for Idenetifying Seismic Deformation Field Anomalies

介绍一种获取地震形变场异常的应变场云图方法。首先在指定时间窗内对GPS位移时间序列进行拟合速度值、插值速度场和计算应变场处理,然后以一定步长滑动得到时空连续的应变场动态变化图像,进而提取形变场异常信息。通过分析门源M_(S)6.4地震与震前应变场时空演化对应关系,说明本方法对预测地震有一定的指示作用。在2019年年终会商中,对嫩江M_(L)4.5地震提出预测意见并检验了实用性。研究认为,应变场云图是一种有效、直观识别震前形变场异常的方法,可在地震会商工作中推广应用。

This paper introduces a method to obtain the anomaly of seismic deformation field by strain field cloud map.The basic idea is as follows.Firstly,we fit the GPS displacement time series in the specified time window,interpolate the velocity field and calculate the strain field.Then we obtain the cloud map of the strain field which varies continuously in space-time sliding with a certain step length and extract the anomaly information of seismic deformation field.We analyzed the relationship between strain field cloud map and Menyuan M_(S)6.4 earthquake.The results show that this method has certain indicative effect on earthquake.At the 2019 year-end provincial Seismologic Consideration,the practicability of this method is tested by predicting Nenjiang M_(L)4.5 earthquake.The research shows that this method is an effective and intuitive method to identify abnormal deformation field before earthquake.