川滇地区公共莫霍界面模型2.0版本构建  

Community Moho interface model in SE Tibet based on several new generation velocity models

作　　者：刘慧杰 王未来[1,4] 张龙 蔡光耀 包晶晶 LIU HuiJie;WANG WeiLai;ZHANG Long;CAI GuangYao;BAO JingJing(Institute of Geophysics,China Earthquake Administration,Beijing 100081,China;Center for Geophysical Survey,China Geological Survey,Langfang Hebei 065000,China;Technology Innovation Center for Earth Near Surface Detection,China Geological Survey,Langfang Hebei 65000,China;Beijing Baijiatuan Earth Sciences National Observation And Research Station,Beijing 100081,China)

机构地区：[1]中国地震局地球物理研究所,北京100081 [2]中国地质调查局地球物理调查中心,河北廊坊065000 [3]中国地质调查局地球浅地表探测技术创新中心,河北廊坊065000 [4]北京白家疃地球科学国家野外科学观测研究站,北京100081

出　　处：《地球物理学报》2025年第3期827-844,共18页Chinese Journal of Geophysics

基　　金：深地国家科技重大专项中生代东亚汇聚岩石圈巨变与浅层响应项目(2024ZD1001100);基本科研业务费专项(DQJB24Z06);中国地质调查局地质调查项目(DD20243193)共同资助。

摘　　要：高分辨率公共速度模型是深入开展地震学研究的重要基础,基于公共速度模型进一步获得高精度公共莫霍界面模型,可以更好地为地壳结构和地球深部动力学研究提供支持.本文基于川滇地区三个新一代高分辨率速度模型建立公共莫霍界面模型,进一步扩充公共速度模型的适用范围.在模型构建之前,首先采用基于已知波速比的接收函数叠加方法(H_(-κ0)叠加)直观的了解每个台站对莫霍面起伏的影响.通过H_(-κ0)叠加,发现许多台站的接收函数多次波与理论到时拟合较差,获得的地壳厚度与人工测深结果差异较大.从波速比分布图像上来看,三个速度模型的波速比横向变化范围很小,部分区域结果与其他学者的研究结果存在差异,这会导致莫霍面估算不准确.为获得相对可靠的莫霍面模型,我们分别只基于VP模型或VS模型来进行H_(-κ)叠加.叠加结果表明基于V_(P)模型之间的差异相对较小,获得的地壳厚度结果与人工测深结果变化特征一致,说明VP模型比VS模型更可靠.因此,我们选用基于三个V_(P)模型H-κ叠加得到的莫霍面结果,并将它们的平均值作为第二版川滇地区公共莫霍界面模型(SWChina CVM-MOHO-2.0).In-depth seismological research relies heavily on the high-resolution community velocity model,and the study of crustal structure and deep Earth dynamics can be better supported by developing the high-precision community Moho interface model based on the community velocity model.To further extend the applications of community velocity model,we develop the community Moho interface model in this study using three newgeneration high-resolution velocity models in the Sichuan-Yunnan area.First,we have an initial knowledge on the response of Moho surface for each station using H_(-κ0)stacking.The receiver function multiple waves of several stations are found to be poorly suited to the theoretical arrivals by H_(-κ0)stacking,and the derived crustal thicknesses show a significant difference from those results revealed by Deep Seismic Sounding.Three velocity models result in inaccurate Moho surface assessment because,according to the distribution images of velocity ratios,they have a narrow lateral variation range of wave velocity ratios and significantly diverge from previous studies.We conducted H_(-κ) stacking only using VP or VS model in order to obtain a reasonably reliable Moho surface model.The findings suggest that the V_(P) model is more trustworthy than the VS model since the variation characteristics of the acquired crustal thickness are consistent with Deep Seismic Sounding results and the discrepancy between the overlaid results based on the V_(P) model is relatively minor.As a result,we choose the crust thickness results using H_(-κ)stacking of the three VP models,and take their average value as SWChinaCVM-MOHO-2.0.

关 键 词：SWChinaCVM-2.0 USTClitho2.0 CSES-VM1.0 接收函数 莫霍界面模型 

分 类 号：P315[天文地球—地震学]