3D主动源地震折射/反射联合快速波前成像研究

基于深地震测深震相记录特征及最新发展起来的快速波前追踪方法,利用理论合成的3D主动源地震折射/反射数据,对强速度对比及复杂Moho结构的重建进行数值模拟计算。结果表明,折射震相Pg对上地壳细结构有较高的分辨,宽角反射震相PmP可较好地约束中下地壳及Moho界面的细结构特征,但对浅部结构的分辨力较差,折射和反射地震的联合成像可有效恢复深浅部3D空间的强速度对比结构及Moho界面形态特征。

Joint Inversion of Active Source Seismic Refraction and Reflection  Using Fast Marching Method For 3d Structure

Based on the seismic phase record characteristics of Deep Seismic Sounding and the fast marching method which has been developed recently, numerical simulation of joint inversion of active source seismic refraction and reflection for 3 D structure is given. The results show that the refraction phase Pg has higher resolution for fine upper crustal structures, and that the middle-lower crustal structure and complex Moho geometry can be well recovered with wide angle reflection phase PmP, although it has poor resolution for the shallow structures. The joint inversion can effectively recover 3 D velocity structure in any depth, with strong velocity contrasts and the morphological characteristics of Moho interface.