计算地震波的震中距和走时的的子程序，非常好用的子程序-Subroutine to calculate seismic epicentral distance and travel time, and very easy to use subroutines

计算震中距、方位角和反方位角的Fortran程序。-Calculated the epicenter, and anti-azimuth azimuth Fortran program.

利用球面坐标求震中距，很好用的算法，希望多多交流.(The center distance of spherical coordinates.)

根据地震台测震仪器记录到发生在震中距1 Km范围内的地震，进行p波和s波的波速计算。(The velocity of P and S waves is calculated according to the earthquake recorded by seismometer at seismic station within 1 km of epicenter distance.)