地震正演模拟在高分辨率隐伏断层地震勘探中的应用

Application of Seismic Modeling in the Shallow Seismic Prospecting Methods to Urban Active Fault Detection

应用波动方程有限差分方法人工合成地震记录进行城市隐伏断层的地震勘探。采用适当的差分算法、震源子波以及有效地边界条件和频散消除方法来提高正演模拟的精度和分辨率。结果表明地震数值模拟可以用来分析地层厚度、断层倾角、断层深度以及断裂带宽度等参数对地震记录的影响;通过实际试验数据和正演模拟的合成单炮地震记录的对比,可以快速判断断层的大致位置和断裂带的大致范围以及目标地层的大致深度。该方法能有效辅助实际野外工作中的数据采集参数的估计,提高勘探效率和精度。

The wave equation finite-difference method is used to the synthetic seismic records in the seismic prospecting of shallow high resolution in urban active fault detection. For improving the resolution and prospecting efficiency of the seismic modeling, some suitable finite-difference method, source wavelet, boundery conditions and dispersion elimination method are adopted. The result shows that the seismic modeling can be used to analyse the influence of the stratigraphic thickness and the obliquity, depth and scale of fault on the seismic synthetic common-shot profiles. From comparision this common-shot profiles with the real experimental data, we can approximately determine the location, scale and depth of fault in field work. The method can improve the prospecting efficiency and resolution rate in the shallow seismic prospecting in urban active fault detection.