摘要
利用东北地区111个固定地震台自2012年1月1日至2015年10月1日连续记录,采用最大熵反褶积法得到台站下方远震P波接收函数,使用双台法提取8~160s周期范围内Rayleigh面波相速度频散曲线,联立二者采用Tarantola非线性反演方法,得到7~140km深度范围的横波速度结构。结果表明:研究区中—上地壳的速度结构与地表地貌具有较好的镜像关系;中、下地壳S波速度结构以重力梯度带为界,东西差异明显,以西表现为大面积低速,以东表现为大面积高速。在壳幔过渡带以及下地幔,横波速度变化量较大,在地幔深度,松辽盆地下方呈现出显著的高速异常在100km深度上消失。长白山下方存在明显的低速异常在140km深度依旧存在。
By using the continuous data,recorded by 111 permanent stations from January 1st,2012 to October 1st,2015 in Northeast China,the P-wave receiving function under the station were obtained by the maximum entropy deconvolution method.The rayleigh surface wave phase velocity dispersion curve within the 8~160s cycle is extracted by using the double platform method.The 7~140km depth range transverse wave velocity structure was estimated by using the Tarantola nonlinear inversion method.The results show that the velocity structure of the middle and upper crust has a good mirror relationship with the surface topography.The S-wave velocity structure of the middle and lower crust is bounded by a gravitational gradient zone.The difference between East and West is obvious.The West shows a large area of low speed and the East shows a large area of high speed.In the transition zone of the shell mantle and the lower mantle,the speed of the transverse wave varies greatly.And at the depth of the mantle,the underground side of the Songliao basin shows a significant high-speed anomaly that disappears at a depth of 100km.There is a significant low-speed anomaly below Changbai Mountain that still exists at a depth of 140km.
作者
高业欣
燕云
朱叶琳
李秀丽
雷晨
GAO Ye-xin;YAN Yun;ZHU Ye-lin;LI Xiu-li;LEI Chen(Liaoning Earthquake Agency,Liaoning Shenyang 110034,China)
出处
《防灾减灾学报》
2020年第3期41-46,共6页
Journal of Disaster Prevention And Reduction
关键词
东北地区
接收函数
面波频散
相速度分布
横波速度结构
Northeast China
receiver function
surface wave dispersion
phase velocity distribution
S-wave velocity structure
