摘要
基于云南大理亚失稳台网的震相到时,采用双差层析成像方法对2021年云南漾濞6.4级地震震源区进行P波速度结构反演,进而分析漾濞地震的发震构造。射线分布和棋盘测试都显示亚失稳台网对漾濞地震震源区覆盖得很好,在2~12 km的深度范围内,随着深度增加,P波的速度模型分辨效果越来越好,震源区内分辨率可以达到0.1°×0.1°。反演获得的震源区速度结构具有明显的横向不均匀性,漾濞6.4级地震发生在高低速交界附近的高速体内,地震序列主要沿NW-SE向展布,走向基本平行于维西-乔后断裂。
Based on the seismic phase arrival time of the Dali Earthquake sub-instability seisimc network in Yunnan province,the P-wave velocity structure of the Yangbi M_(S)6.4 earthquake in 2021 in Yunnan Province was inverted by double-difference tomography,and then the seismogenic structure of the earthquake was analyzed.Both ray distribution and checkerboard test show that the Yangbi seismic source area is well covered by the sub-instability network.In the depth range from 2 km to 16km,the resolution of P-wave velocity model becomes better and better with the increase of depth,and the resolution in the source area can reach 0.1°×0.1°.The velocity structure of the Yangbi M_(S)6.4 earthquake occurred in the high velocity body near the boundary between high and low velocity,and the seismic sequence mainly distributed along the NW-SE direction,which was basically parallel to the Weixi-Qiaohou fault.There are low velocity anomalies in the north and south of the Yangbi earthquake sequence,and the high velocity anomalies may block the NW-trending rupture of the Yangbi earthquake,thus causing the SE-trending rupture of the seismic sequence.
作者
赵志远
王晓山
陈婷
冯向东
ZHAO Zhiyuan;WANG Xiaoshan;CHEN Ting;FENG Xiangdong(Hebei Earthquake Agency,Shijiazhuang 050021,China)
出处
《华北地震科学》
2022年第1期58-63,共6页
North China Earthquake Sciences
基金
国家重点研发计划项目(2018YFC150330304)。
关键词
亚失稳台阵
漾濞地震
双差层析成像
P波速度分布
sub-instability seismic station array
Yangbi earthquake
double-difference tomography
P-wave velocity distribution