近地表速度变化对地震波传播的影响  

Effect of velocity variation on seismic wave propagation in near surface

作　　者：张兵[1] 方伍宝[1] 孔祥宁[1] 李满树 

机构地区：[1]中国石油化工股份有限公司石油勘探开发研究院南京石油物探研究所,江苏南京210014

出　　处：《勘探地球物理进展》2008年第5期357-362,共6页Progress in Exploration Geophysics

摘　　要：地表起伏和近地表速度变化是影响地震波传播的两个重要因素。采用基于坐标变换的起伏地表弹性波正演模拟方法,对纵向变速、横向变速、随机变速等一系列速度模型进行了正演数值模拟,分析了起伏地表情况下近地表速度的不同变化对正演模拟记录的影响,得出近地表变速带厚度较薄、纵向层状变速明显、横向块状变速剧烈以及介质速度随机变化较大时都会导致噪声严重、模拟记录信噪比变低的结论。Rugged surface and velocity variation in near-surface are two important factors that impact seismic wave propagation. With transformation of rugged topographic coordinate, we carried out forward numerical simulation on vertically variable velocity model, horizontally variable velocity model, and randomly variable velocity model, and analyzed the effect of velocity variation in near surface on the results of simulation. It is concluded that the thin variable velocity layer, significant layering variations of velocity, sharply bulky lateral variations of velocity, and large random velocity variation will all result in records of serious noises and low signal-to-noise ratio.

关 键 词：起伏地表 坐标变换 纵向变速 横向变速 随机变速 

分 类 号：P631.4[天文地球—地质矿产勘探]