李乐1,,
1. 中国地震局地震预测研究所(地震预测重点实验室), 北京 100036
2. 辽宁省地震局, 沈阳 110034
基金项目: 国家自然科学基金(41874064)和地震预测研究所基本科研业务专项(2015IES010203)共同资助
详细信息
作者简介: 孙庆山, 男, 助理工程师, 主要从事数字地震学研究.E-mail:ilovefushun@126.com
通讯作者: 李乐, 女, 研究员, 硕士生导师, 主要从事板内重复地震与活动构造研究.E-mail:lile@ief.ac.cn
中图分类号: P315收稿日期:2019-01-17
修回日期:2019-04-18
上线日期:2020-02-05
Deep slip rates along the northern segment of the Red River fault zone estimated from repeating microearthquakes
SUN QingShan1,2,,LI Le1,,
1. Key Laboratory of Earthquake Prediction, Institute of Earthquake Forecasting, China Earthquake Administration, Beijing 100036, China
2. Liaoning Earthquake Agency, Shenyang 110034, China
More Information
Corresponding author: LI Le,E-mail:lile@ief.ac.cn
MSC: P315--> Received Date: 17 January 2019
Revised Date: 18 April 2019
Available Online: 05 February 2020
摘要
摘要:利用云南数字地震台网1999-2015年的波形资料,通过识别在断层同一位置发生的重复微震来估算红河断裂带北段不同孕震深度的断层滑动速率.针对研究区台站分布稀疏的客观情况,采用基于子采样条件下S-P相对到时差约束地震相对位置,从而确保震源位置一致性的方法,在红河断裂带北段及其附近区域识别出23组重复微震,其复发间隔变化明显.重复微震的时空变化初步分析表明,研究区频繁的背景地震活动和相邻较近的重复微震之间的相互作用都会对重复微震的复发间隔产生影响.利用重复微震的震级和复发间隔,估算得到红河断裂带北段6.0~13.4 km孕震深处的滑动速率为2.3~10.0 mm·a-1,显示不同孕震深度的滑动速率存在差异.
关键词: 红河断裂带北段/
重复微震/
深部滑动速率
Abstract:Deep slip rates at depths along the northern segment of the Red River fault zone were estimated using repeating microearthquakes between 1999 and 2015 recorded by the Yunnan Seismic Network (YSN). Due to the sparsity of the network stations in the study area, we used an empirical method to constrain the relative distance between event pairs based on S-P differential times measured at subsample accuracy. Using this method, we finally identified a total of 23 sequences of repeating microearthquakes. In each sequence, the occurrences of the earthquakes are rather aperiodic. Based on the spatial-temporal distribution of repeating sequences, we found that the changing of the stress field caused by large earthquakes occurred near the repeating sequences may cause the reduction of recurrence intervals. Some repeating sequences are located closely, the interactions between these sequences are tied to the irregularity of earthquake recurrence. Based on the magnitudes and recurrence intervals of the repeating sequences, we computed the fault slip rates along the northern segment of the Red River fault zone varies from 2.3 to 10.0 mm·a-1 at the depth range of 6.0~13.4 km, and shows substantial difference at different seismogenic depths.
Key words:Northern segment of the Red River fault zone/
Repeating microearthquakes/
Deep slip rates
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