提高山区地震叠加速度精度的试验

EXPERIMENTATION FOR ACQUIRING MORE ACCURATE SEISMIC STACK VELOCITY DATA IN MOUNTAINOUS REGION

地质矿产部第二物探大队

本文从四川地震工作的实际出发,通过理论模型计算,论证了在地形起伏较大的丘陵山区剩余静校正是影响叠加速度精度的重要因素之一。为了提高叠加速度的精度,获得较高精度的速度谱,应该采取速度谱—剩余静校—速度谱的循环迭代处理方法。在此基础上,对实际地震资料进行了试处理,并对反褶积、一次剩余静校、二次剩余静校后的速度谱进行了比较,计算了均方差,取得了与理论模型基本一致的结果。文章最后介绍了实现该方法的处理流程和参数选择问题。本文提出的方法简单易行,完全可以在小型计算机上实现。

Based on the seismic survey performed in Sichuan and by theoretical model calculation, it has been proved that the residual static correction should be considered as one of the important factors affecting stack velocity's accuracy in the quite rugged hilly areas. For obtaining more desirable stack velocity data as well as spectrum, the iteration cycling way of data handling is recommendable i.e. velocity spectrum-residual static correction-velocity spectrum. On this basis, a series of work were done such as preprocessing the field seismic data ; Comparing the deconvolution with the spectra after primary and secondary residual static correction; and calculating the rms difference. Consequently, the result turned out could be basically matched with that of theoretical model. Also, the processing sequence and selecting parameters for implementing this technique are presented at the end of this paper.The technique suggested in the paper reveals itself simple and easy.It will have no problem at all to work on the minicomputers, the author remarked.