Scholte wave dispersion and particle motion mode in ocean and ocean crust  

海洋和洋壳中Scholte波的频散及质点运动方式

作　　者：Xu Xin Wan Yong-Ge Li Zhen-Yue Sheng Shu-Zhong 许鑫;万永革;李振月;盛书中(防灾科技学院,河北三河065201;中国科学技术大学,合肥230026;中国地震局地球物理研究所,北京100081;东华理工大学地球物理与测控技术学院,南昌330013)

机构地区：[1]Institute of Disater Prevention of Science and Technology,Sanhe 065201,China [2]University of Science and Technology of China,Hefei 230026,China [3]Institute of Geophysics,China Earthquake Administration,Beijing 100081,China [4]School of Geophysics and Measurement-control Technology,East China University of Technology,Nanchang 330013,China

出　　处：《Applied Geophysics》2022年第1期132-142,146,共12页应用地球物理（英文版）

基　　金：supported by the National Natural Science Fondation of China(Nos.42174074,41674055,41704053);the Earthquake Science Spark Program of Hebei Province(No.DZ20200827053);Fundamental Research Funds for the Central Universities(No.ZY20215117);the Hebei Key Laboratory of Earthquake Dynamics(No.FZ212105).

摘　　要：The dispersion equation of the Scholte wave was reviewed using the homogeneous elastic half-space covered by a liquid layer,and the range of the Scholte wave propagation velocity was examined using the dispersion equation.The displacement expressions of the Scholte waves in liquid and solid were derived.Additionally,the mode of motion of Scholte waves in liquid and solid and their variation with depth was studied.The following results were obtained:The dispersion equation shows that the propagation velocity of the fundamental Scholte wave was greater than the P-wave in liquid and less than that of the Scholte wave in homogeneous elastic half-space.In contrast,the velocity of higher-order Scholte waves was greater than that of P waves in liquid and S-waves in solid.Only the fundamental Scholte wave has no cutoff frequency.The Scholte wave at the liquid surface moved only vertically,while the particles inside the liquid medium moved elliptically.The amplitude variation with depth in the solid medium caused the particle motion to change from a retrograde ellipse to a prograde ellipse.The above results imply the study of Scholte waves in the ocean and oceanic crust and help estimate ocean depths.基于均匀弹性半空间上覆液体层的模型,回顾了Scholte波的频散方程,并根据频散方程分析了Scholte波传播速度的范围。推导了液体和固体中Scholte波的位移表达式,研究了液体和固体中Scholte波的运动方式及其随深度的变化。获得以下认知:频散方程表明基阶Scholte波的传播速度大于液体中的P波速度但小于均匀弹性半空间的Rayleigh波速度,其它阶Scholte波的传播速度大于液体中的P波速度小于固体中的S波速度;仅基阶Scholte波无截止频率。液体表面Scholte波仅有竖直方向的运动,液体内部质点做逆进扁椭圆方式的运动。固体中,振幅随深度的变化导致质点的运动方式由逆进椭圆过渡为顺进椭圆,椭圆形态均为长椭圆。以上结果对研究海洋和洋壳中的Scholte波以及估算海洋深度有一定的参考意义。

关 键 词：Scholte waves in the ocean and oceanic crust dispersion equation propagation velocity amplitude mode of motion 

分 类 号：P631[天文地球—地质矿产勘探]