中国地震台网初至P波区域三维走时表的建立

基于LLNL-G3Dv3全球P波三维速度模型，应用FMM软件包计算并建立了中国地震台网990个台站的初至P波区域三维走时表．该走时表覆盖了以台站为中心的水平向20°×20°、 垂直向-5.1—80 km （向下为正）的三维空间. 其水平向间隔为0.2°，垂直向间隔为5 km．这样对于任一深度小于80 km的震源，均可以应用此三维走时表计算其到周围10°范围内台站的走时．中国地震台网初至P波区域三维走时表的建立，对于改善区域初至P波走时预测，提高地震定位精度有一定现实意义．

Construction of regional three-dimensional travel-time tables of first P arrival for China Seismograph Network

Based on the global-scale three-dimensional P wave velocity model LLNL-G3Dv3，regional travel-time table of first P arrivals of 990 seismic stations of China Seismograph Network is calculated and constructed by using FMM software package. The table covers the station-centered area with 20° multiply 20° in horizontal direction and -5.1 km to 80 km in vertical direction. The horizontal interval of travel-time table is 0.2° and the depth interval is 5 km. Accordingly，travel-times can be calculated within the distance of 10° for any source with depth less than 80 km. As a consequence of the construction of the regional three-dimensional first P arrival travel-time table，the prediction of first P arrival time would be much more improved，and it is significant for improving earthquake locations.