地震地磁观测与研究2025，Vol.46Issue(3)：12-23,12.DOI:10.3969/j.issn.1003-3246.2025.03.002
基于H-k方法的云南元江地震台下方地壳厚度和泊松比反演
The inversion of crustal thickness and Poisson's ratio beneath Yuanjiang seismic station in Yunnan Province based on the H-k stacking method
摘要
Abstract
Yunnan Yuanjiang seismic station(YN.YUJ)is located along the Xiaojiang Fault zone on the southeastern margin of the Qinghai-Xizang Plateau.This study is based on the seismic waveform data collected from 2007 to 2017,which includes earthquakes with magnitudes greater than 6.4 and epicentral distance ranging from 28° to 95°.Using iterative time-domain deconvolution method,we extracted 376 high-quality P-wave receiver functions.The azimuthal variation of Moho Pms conversion phase in the receiver functions provides robust evidence for probing the crustal anisotropy.In this paper,the receiver functions of YN.YUJ are corrected to the epicentral distance of 67°,and then stacked according to the back-azimuth intervals of 10°.The grid search method is applied to fit the Pms phase arrival time on the stacked traces in order to obtain the crustal anisotropy parameters:Pms phase splitting time of YN.YUJ is 0.48±0.09 s,and the polarization direction of fast wave is-59°±3.81°.The crustal thickness and wave velocity ratio obtained by the traditional receiver function H-k stacking method are 38±2 km and 1.71±0.05,respectively,and corresponding to a Poisson's ratio of 0.24.In contrast,the improved H-k stacking method which is considered anisotropy refined these results to 35.6±1 km and 1.75±0.06,with a Poisson's ratio of 0.26.The results reveal that the fast-wave polarization aligns SE-NW,parallel to the southern segment of the Red River Fault,suggesting the crustal deformation beneath the station is controlled by tectonic fault motion.The discrepancies between the two sets of stacking results suggest that,in regions with strong subsurface anisotropy,using the improved H-k stacking method yields more reliable estimates of crustal thickness and Poisson's ratio.关键词
P波接收函数/地壳各向异性/H-k叠加方法/地壳厚度/泊松比Key words
P-wave receiver function/crustal anisotropy/H-k stacking method/crustal thickness/Poisson's ratio引用本文复制引用
苟一心,缪谊芳,王先星,杨海燕..基于H-k方法的云南元江地震台下方地壳厚度和泊松比反演[J].地震地磁观测与研究,2025,46(3):12-23,12.基金项目
国家自然科学基金(项目编号:42174064) （项目编号:42174064）
云南省"兴滇英才"青年人才项目 （）
云南大学研究生科研创新基金项目(项目编号:KC-23234745) （项目编号:KC-23234745）
