李洪丽^1,,
刘财^1,2,
田有^1,2,3,,,
吴兆营⁴,
朱洪翔¹
1. 吉林大学地球信息探测仪器教育部重点实验室, 长春 130026
2. 吉林大学地球探测科学与技术学院, 长春 130026
3. 长白山火山综合地球物理教育部野外科学观测研究站, 长春 130021
4. 吉林省地震局, 长春 130021

基金项目: 国家自然科学基金项目(41874049)、国家重点研发计划"深地资源勘查开采"项目(2017YFC0601300)、吉林省重点科技攻关项目(20150204002SF)和中央高校基本科研业务费项目联合资助


详细信息

作者简介: 李洪丽, 女, 1981年生, 博士研究生, 从事地震活动性、地壳速度成像等研究工作.E-mail: lihongli@jlu.edu.cn

通讯作者: 田有, 男, 1979年生, 教授, 从事地球内部结构成像研究工作.E-mail: tianyou@jlu.edu.cn

中图分类号: P315

收稿日期:2020-08-04
修回日期:2020-12-28
上线日期:2021-05-10

Seismic tomography of the Songyuan area, Northeast China: constraints on seismogenic structure

LI HongLi^1,,
LIU Cai^1,2,
TIAN You^1,2,3,,,
WU ZhaoYing⁴,
ZHU HongXiang¹
1. College of Geo-exploration Science and Technology, Jilin University, Changchun 130026, China
2. Key Laboratory of Geophysical Exploration Equipment, Ministry of Education, Jilin University, Changchun 130026, China
3. Changbaishan Volcano Geophysical Observatory, Ministry of Education, Changchun 130021, China
4. Earthquake Administration of Jilin Province, Changchun 130021, China


More Information

Corresponding author: TIAN You,E-mail:tianyou@jlu.edu.cn

MSC: P315

--> Received Date: 04 August 2020
Revised Date: 28 December 2020
Available Online: 10 May 2021


摘要
摘要:本文选取2013年10月到2018年12月期间松原市周边17个地震台记录到的515个地震事件的2926条P波和2665条S波到时数据，采用双差成像方法联合反演松原地震区震源参数和中上地壳(0~25 km)高分辨率三维体波速度和波速比结构，进而利用O'Connell-Budiansky理论估计了该区岩石介质的裂缝密度和饱和度参数.重定位后的震源参数精度有了显著提高.松原震区P波和S波的速度、波速比结构均表现出明显的不均匀特性，主要表现为低P波、低S波、低波速比结构，推测松原地震区发生更大地震的可能性较低.松原震群区浅地表区域(< 5 km)整体表现为低P波、低S波和高波速比结构，而岩石介质的裂缝密度和饱和度表现为高值.浅层高波速比、高裂缝密度和高饱和度结构可能与流体有关；从区域构造出发表明松原地震发震构造与东北地区的区域构造应力场密切相关.松原震区的三维精细速度和高精度震源位置信息为深入了解该地区的地壳结构、孕震构造和地震活动性提供重要参考.
关键词: 双差层析成像/
中国东北/
松原地震/
速度结构/
孕震构造

Abstract:In this paper, we selected 2926 P-wave and 2665 S-wave arrival times of 515 seismic events recorded by 17 seismic stations around the Songyuan area, Northeast China from October 2013 to December 2018. We used the double-difference tomography method to determine the hypocentral parameters and the high-resolution 3D body wave velocity, velocity ratio (V_P/V_S) structure of the middle and upper crust (0~20 km) beneath the Songyuan area, and then estimated the parameters of crack density and saturation rate of rock. The accuracy of the source parameters was improved significantly after relocation. The P- and S-wave velocity and V_P/V_S in this area show obvious non-uniformity, characterized by low P-wave, low S-wave velocity and low V_P/V_S beneath 5 km depth. Overall, the shallow crust (< 5 km) has low P-wave and low S-wave velocity, high V_P/V_S ratio, and big anomalies of crack density and saturation degree, which may be related to fluids in the crust. In view of the regional tectonics, the seismogenic structure of the Songyuan area is closely related to the regional tectonic stress field in Northeast China. The high-resolution three-dimensional velocity structure and high precision hypocentral location of the Songyuan area presented in this paper provide an important reference for the further understanding of the crustal structure, seismogenic structure and earthquake activity in this region.
Key words:Double-difference tomography/
Northeast China/
Songyuan area/
Velocity structure/
Seismogenic structure



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