起伏地表初至波与反射波联合层析成像在地质勘探中的应用

Joint tomography with seismic first-break and reflection under rugged topographical conditions in geological exploration

地震层析成像技术是通过观测并收集地震波传播时间相关数据,重建地质模型进行地球物理反演,从而得到地下介质构造、速度分布等相关信息的一种方法。为解决起伏地表条件下层析成像相关问题,本文利用混合网格LTI (Linear Traveltime Interpolation)算法,使网格剖分对起伏地表及地下构造变化大的区域有较高的拟合度,结合LSQR(Least squares QR)反演算法实现了起伏地表地震初至波与反射波联合层析成像,为起伏地表下介质的成像问题开拓一条新思路。经过理论模型测试,验证了该算法的有效性和稳定性。

Seismic travel-time tomography is one of method that using geophysical technology to inverse information about underground medium and velocity distribution by collecting seismic traveltime data. In order to solve the problem about seismic tomography under rugged topographical conditions. The author develops a new way for seismic tomography by combine LTI method based on hybrid meshes which has high fitting degree for the variable structure underground with LSQR algorithm. Thus, the joint tomography technology with seismic first-break and reflection under rugged topographical conditions has been achieved. The stability and effectiveness is verified by theoretical model test.