高频GPS测定的尼泊尔M_W7.8和M_W7.3地震震时地表动态变形过程

Measuring Ground Deformations Caused by Nepal M_W7.8 and M_W7.3 Earthquakes Using 1 Hz GPS Data

以陆态网络和尼泊尔境内高频(1Hz)GPS观测数据为基础,采用动态双差相对定位方法,获取2015年尼泊尔M_W7.8和M_W7.3地震震时近场地表动态变形过程。结果表明,M_W7.8地震震中东侧高频GPS站动态位移幅度明显大于震中西侧;各高频GPS站动态位移幅度不仅与测站震中距有关,而且与地震破裂传播方向有关;M_W7.3地震引起的水平动态位移相对较小。将高频GPS与邻近强震仪动态位移时序进行对比发现,二者在振幅和相位上具有较好的一致性。

We derive dynamic ground deformations caused by the 2015 Nepal Mw7.8 and Mw7.3 earth- quakes on the basis of 1 Hz GPS data of crustal movement observation network of China （CMONOC） and Nepal using kinematic relative positioning method. The results show that the displacement ampli- tudes of eastern GPS sites of the MwT. 8 earthquake are larger than the western. The kinematic de- formations of each station arenot only associated with epicentral distance hut also earthquake rupture propagation directivity. Dynamic ground motions caused by the MwT. 3 earthquake are small. We find good agreement between high-rate GPS and strong motion displacements time series.