学术
基阶与高阶瑞利波联合反演研究
罗银河[1] 夏江海[1,2] 刘江平[1] 刘庆生[1]
[1]中国地质大学（武汉）地球物理与空间信息学院,武汉430074 [2]堪萨斯大学堪萨斯地质调查所,美国堪萨斯,劳伦斯66044—3726,美国
摘 要:
研究了六层层状介质模型瑞利波基阶和高模式波相速度对横波速度、深度的敏感性,结果表明：基阶波较高模式波对7m以内浅部地层的横波速度更敏感,敏感性频带在10-25Hz范围内,峰值频带集中在18Hz左右;高模式波较基阶波对深部地层的横波速度更敏感,敏感性频带宽,峰值分散.基阶波对浅层的敏感性和高模式波穿透深度更深的特点为近地表岩土层二维横波速度结构的联合反演提供了前提条件.利用阻尼最小二乘SVD（Singular Value Decomposition）算法联合基阶与高模式波对理论模型和实例数据进行横波速度反演,反演结果表明联合反演增强了反演的稳定性,提高了反演的精度.[著者文摘]
文章出处:
《地球物理学报》-2008年51卷1期 -242-249页
分 类 号:
文章编号:
0001-5733（2008）01-0242-08
Joint inversion of fundamental and higher mode Rayleigh waves
LUO Yin-He , XIA Jiang-Hai, LIU Jiang-Ping , LIU Qing-Sheng（ 1. Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan 430074, China; 2. Kansas Geological Survey, The University of Kansas, 1930 Constant Avenue, Lawrence, Kansas 66047-3726, USA）
Abstract:
In this paper, we analyze the characteristics of the phase velocity of fundamental and higher mode Rayleigh waves in a six-layer earth model. The results show that fundamental mode is more sensitive to the shear velocities of shallow layers （ 〈 7 m） and concentrated in a very narrow band （around 18 Hz） while higher modes are more sensitive to the parameters of relatively deeper layers and distributed over a wider frequency band. These properties provide a foundation of using a multi-mode joint inversion to define S-wave velocity. Inversion results of both synthetic data and a real-world example demonstrate that joint inversion with the damped least squares method and the SVD （Singular Value Decomposition） technique to invert Rayleigh waves of fundamental and higher modes can effectively reduce the ambiguity and improve the accuracy of inverted S- wave velocities.[著者文摘]
Key words:
Rayleigh waves, Fundamental mode, Higher mode, Sensitivity, Joint inversion
基金资助:
国家自然科学基金项目（40474025）资助. 致谢 实例数据由美国堪萨斯大学地质调查所提供;感谢湖北省科技厅国际合作处提供赴美资金使本文摘要得以学术交流;感谢美国堪萨斯大学Rick Miller副教授、W.E.Doll教授对本文提出的宝贵建议.
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