随机介质模型中瑞雷波正演模拟及波场特性分析  

The forward modeling of Rayleigh wave and analysis of wave field characteristics based on random medium model

作　　者：赵宏欣[1] 熊章强[1,2] 张大洲[1,2] 

机构地区：[1]中南大学地球科学与信息物理学院,长沙410083 [2]中南大学有色金属成矿预测教育部重点实验室,长沙410083

出　　处：《物探化探计算技术》2016年第6期780-787,共8页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：国家自然科学基金(41274123);博士点基金(20130162110066)

摘　　要：为了研究介质的不均匀性对瑞雷波波场特性的影响,利用高精度交错网格法对不同自相关长度的随机介质模型在不同震源主频率时的波场进行了正演模拟,并应用相移法提取了频散曲线。通过对比波场快照、单道记录及分析频散曲线可以得出:随机介质中的不均匀体会导致瑞雷波传播能量的减弱,并使波的到达时间发生变化;大于或与波长相当的不均匀体随机介质以及由细密薄层构成的地层介质对频散曲线影响较大,这种情况下进行瑞雷波勘探时不能将其视为均匀介质。To study the effect of Rayleigh wave field characteristic in heterogeneity medium,high accuracy staggered grid method has been applied into random medium models with different autocorrelation length at a different main frequency source.Basis on this,we have got dispersion curve by the phase shift method and contrast snapshots,single-channel recording and dispersion curve.The results shows that the Rayleigh wave energy of random medium is less than that in a homogeneous medium,and the arrival time in random mediums changes caused by irregularities.The random medium whose size of irregularities greater than or comparable to the wave length and the stratum medium constituted by a fine thin layer influences more on the dispersion curve,we can＇t see them as homogeneous mediums for Rayleigh wave exploration in this case.

关 键 词：随机介质 瑞雷波 频散曲线 波场特性 

分 类 号：P631.4[天文地球—地质矿产勘探]