基于GPS TEC的尼泊尔MW7.8地震同震电离层扰动研究

Research on Co-Seismic Ionospheric Disturbance Due to the Nepal MW7.8 Earthquake Based on GPS TEC

基于GPS数据对2015年尼泊尔M W7.8地震引起的同震电离层扰动进行统计与FFT频谱分析,探究地震电离层TEC扰动传播的时空特性。结果表明,震后5 min起出现明显的TEC扰动异常现象,持续时间超过6 min,呈现增大-减小-增大的变化趋势;扰动由震中向东、东北等方向传播,速率分别为2336.36 m/s和455.52~937.64 m/s;扰动的中心频率为3~7 mHz,符合瑞利波与声波引发的扰动频段。

In this paper,we calculate the ionospheric TEC disturbance caused by the 2015 M W7.8 Nepal earthquake and analyze the FFT spectrum based on GPS observation data to research temporal and spatial characteristics of earthquake ionospheric TEC.The results show that obvious abnormal disturbance appears 5 minutes after earthquake and lasts more than 6 minutes with a trend of increasing-decreasing-increasing.The disturbance propagates towards east,northeast and several directions,whose velocities are 2336.36 m/s and 455.52-937.64 m/s.The center frequencies are mostly 3-7 mHz,which is consistent with the disturbance spectrum caused by Rayleigh wave and acoustic wave.