地声与地震相关性的初步探讨

为探索震前声发射的方向与地震的关系,假定声速仅与深度有关,在这种条件下得到的方向公式应该与恒速条件下得到的方向公式一致。为了简化起见,可以用实测时差作为公式中的时差,其误差是允许的。报告中介绍了用互相关函数求时差的方法,并给出部分地声方向的计算结果,初步表明震前声发射的方向与未来震中有着密切关系。

A PRIMARY STUDY ABOUT THE DIRECTION OF ACOUSTICAL EMISSION PRIOR TO EARTHQUAKES

For exploring the direction of acoustical emission sources prior to earthquakes, assuming that the sound velocity is only dependent on depth, a formula of sound source direction can be derived. The formula should be such that the result should agree with that obtained under the condition of constant sound velocity. For simplification, the time differences can be replaced by the actual time differences between two recievers, and the error thus caused can be permited. In the report, the crosscorrelation method is introduced to calculate the time difference between two signals. Finally, an actually computed result is given, which shows that the direction of acoustical emission prior to earthquakes is closely related to the future epicenters.