远震数据显示贝加尔裂谷带北穆伊斯克(Severomuysk)段地壳和上地幔的精细结构  

Detailed structure of the Earth’s crust and upper mantle of the Severomuysk segment of the Baikal rift zone accordingto teleseismic data

作　　者：Valentina V.MORDVINOVA Maria A.KHRITOVA Elena A.KOBELEVA Mikhail M.KOBELEV Evgeniy Kh.TURUTANOV Victor S.KANAYKIN 

机构地区：[1]Institute of the Earth’s Crust Siberian Branch of the Russian Academy of Science,Irkutsk 664033,Russia [2]Baikal Branch of the Geophysical Service of the Russian Academy of Science,Irkutsk 664033,Russia [3]Irkutsk National Research Technical University,Irkutsk 664074,Russia

出　　处：《地学前缘》2022年第2期378-392,共15页Earth Science Frontiers

摘　　要：通过贝加尔裂谷系统北穆伊斯克(Severomuysk)段的密集地震台站线性网络获得的远距离强震记录,并利用P波接收函数技术,揭示了地壳和上地幔顶部的复杂分层块状结构。横波速度的分布表明构成北穆伊斯克地壳的地块具有不同性质。这些地块的西部聚散和地壳下部的分层证实了该地区隆起的堆积-碰撞起源。位于西伯利亚克拉通变薄的倾斜边缘上的北穆伊斯克段解释了该地区地壳碰撞效应的强度。2015年地震的震中深度与Muyakan凹陷地壳上部的明显速度差异存在令人信服的相关性。The records of distant strong earthquakes,obtained by way of a dense linear network of seismic stations in the Severomuysk segment of the Baikal rift system,revealed a complex layered-block structure of the Earth’s crust and subcrustal mantle using the longitudinal receiving function.The distribution of crosswave velocities indicates that the properties of the blocks that make up the Severomuysk Earth’s crust differ.The western vergence of these blocks and the stratification of the lower part of the Earth’s crust confirm the accretion-collision origin of the uplift.The intensity of the collision effect on the Earth’s crust of the region is explained by the location of the Severomuysk segment on the thinned inclined edge of the Siberian Craton.A convincing correlation was found between the focal depths of earthquakes in 2015and contrasting velocity heterogeneities in the upper part of the Earth’s crust of the Muyakan depression.

关 键 词：地球物理学 P-波接收函数 地震速度剖面 西伯利亚克拉通 贝加尔裂谷带 

分 类 号：P315.2[天文地球—地震学] P542[天文地球—固体地球物理学]