利用高频GPS数据反演地震要素

Estimation of seismic elements from high-rate GPS observations

  • 摘要: 介绍了利用高频GPS观测数据反演地震要素的原理和方法. 以2019年7月4日和7月6日发生在美国加州里奇克莱斯特的地震为研究对象,首先利用PRIDE PPP-AR软件进行动态精密单点定位解算以获得测站的位移时间序列,然后使用S变换对位移时间序列去噪,再根据去噪后的时间序列提取地震波的振幅与周期,并提出双重3-sigma法则以分别提取地震波的体波和面波到达时,最后据此反演出地震的震中位置、震级以及发震时刻. 根据本文提出的方法反演得到的震中位置与美国地质勘探局(USGS)发布的位置偏差在10 km左右,震级偏差在0.2级左右,发震时刻偏差在20 s以内. 结果表明,利用高频GPS数据可以较为准确地反演出地震要素.

     

    Abstract: In this paper, theories and methods of estimating seismic elements from the high-rate GPS observations were presented. Selecting July 4th, 2019 and July 6th, 2019 Ridgecrest earthquakes as the research object, kinematic precise point positioning (PPP) was used to obtain the time series of displacement, then S transform algorithm was chosen to eliminate the noise of displacement time series, and the amplitude and period of the seismic wave were extracted from the denoised time series, and then we came up with the double 3-sigma rules to pick up the arrival time of body waves and surface waves, at last estimated the location of epicenter, magnitude and origin time of the earthquakes. Compared with the seismic elements provided by USGS, the deviation of the epicenter was about 10 km, the magnitude deviation was around 0.2, and the deviation of origin time of earthquakes was within 20 s. The results showed that the high-rate GPS observations can be used to estimate the seismic elements accurately.

     

/

返回文章
返回