2017年3月27日漾濞5.1级地震前后气枪震源观测走时数据的变化

以2017年3月27日漾濞5.1级地震为例,根据区域特性和信噪比要求,选取数据较为完整的6个台站记录的2017年1月1日～6月6日期间的宾川地震信号发射台气枪震源波形资料,采用互相关检测技术提取6个台站各自稳定震相的走时数据,并对漾濞5.1级地震前后走时数据的变化情况进行分析。结果表明,漾濞5.1级地震前后6个台站各自稳定震相存在较为明显的走时变化,且短期内走时变化具有较好的同步性,相关台站异常幅度大小和异常出现时间存在细小差异。地震发生前,6个台站走时低值异常过程明显,以YUL台最为显著。地震发生前后走时变化形态特征为双“V”型,漾濞5.1级地震发生在第1个“V”型末端。地震发生后,不同方位相关台站受地震的影响程度不同,走时波动大小存在差异。

Travel-time Variations before and after the Yangbi MS5.1 Earthquake on March 27,2017 from the Airgun Source Seismic Data

Taking the Yangbi M_S5.1 earthquake on March 27,2017 as an example,according to the regional characteristics and signal-to-noise ratio requirements,the data from 1 January to 6 June, 2017 recorded by 6 stations with relatively complete recording were selected. The source waveform data of the airguns of the Binchuan earthquake signal launching platform were used to extract the travel time data of the stable seismic phases of the six stations,and to analyze the changes of the travel-time data before and after the Yangbi M_S5.1 earthquake. The results show that there are obvious time-varying changes in the stable seismic facies of the 6 stations before and after the Yangbi M_S5.1 earthquake,and the short-term transit time has good synchronization. There are small differences between the abnormal amplitude of the relevant stations and the abnormal time. The low-value anomaly process of the 6 stations before the earthquake was obvious,and the YUL station was the most significant. The morphological characteristics of the travel time before and after the earthquake are "double V",and the Yangbi M_S5.1 earthquake occurs at the end of the first "V" shape. After the earthquake,different stations with different orientations are affected by the earthquake,and there are differences in the fluctuations of travel time.