高频GNSS资料的强震震相识别与震中确定

利用2011日本东北Mw9.0地震和2008汶川Mw7.9地震若干台站的高频（1 Hz）GNSS观测资料，通过精密单点定位方法解算出地震发生时的位移形变波形。对位移波形一阶差分得到震时高频GNSS速度时间序列，采用S变换谱的方法对该速度时序进行地震波到时的拾取，即震相识别。将地震波拾取结果用于震中位置和发震时刻反演，并与美国地质调查局USGS公布的资料对比。结果发现，两者日本地震震中位置相差约16 km，发震时刻相差约0.7 s；汶川地震震中相差约4 km，发震时刻相差约0.4 s。

Seismic Phases Identification and Epicenter Determination of Strong Earthquakes with High-Rate GNSS Data

In this paper, we use several stations’ high-rate GNSS observations of the strong earthquakes in Japan on March 11, 2011 and in Wenchuan May 12, 2008 to get the displacement waveforms during the events by means of Precise Point Positioning. From the first-difference displacement waveforms, we get the high-rate GNSS velocity time series, then we use their S transform spectrums to identify seismic phases and pick up the arriving times. The pickup results are applied for the inversion of the epicenter location and the origin time. Compared with the data published by USGS, the difference of the Japanese earthquake epicenter location is about 16 km, the origin time difference is about 0.7 s; the epicenter location difference of Wenchuan event is about 4 km, and origin time difference is about 0.4 s.