气枪主动源与天然地震信号的传播特征对比研究*

(1.云南大学 资源环境与地球科学学院,云南 昆明 650091; 2.云南省地震局,云南 昆明 650224; 3.中国地震局地球物理研究所,北京100081)

宾川主动源; 气枪激发; 地震信号; 聚类分析; 信号叠加; 波形特征; S变换

Comparison of Propagation Characteristics of Signals Triggered by Air-gun Active Source and Natural Earthquakes
XIANG Ya1,WANG Bin2,YANG Runhai2,WANG Weitao3,YANG Haiyan1

(1.School of Resource Environment and Earth Sciences,Yunnan University,Kunming 650091,Yunnan,China)(2.Yunnan Earthquake Agency,Kunming 650024,Yunnan,China)(3.Institute of Geophysics,China Earthquake Administration,Beijing 100081,China)

Binchuan active transmitting seismic station; airgun excitation; earthquake signals; Hierarchical clustering; signal stacking; waveform characteristic; S-transform

备注

应用S变换对比分析云南宾川地震信号发射台单次气枪激发信号与同当量天然地震信号在传播过程中的波形和频率特征,并基于参考台聚类分析结果,对其他接收台站的地震信号进行线性叠加和相位加权叠加,研究结果表明:(1)气枪信号传播过程中主频为3~6 Hz,可以在距离为151 km的台站检测到信号,传播过程中能量衰减较慢。天然地震信号主频较高,在传播7.7 km时的主频为10~20 Hz,传播距离约为60 km,传播过程中能量衰减较快;(2)经过2 000余次的线性叠加和相位加权叠加,可以分别在距离为225 km和350 km的台站检测到气枪信号。与天然地震信号相比,气枪信号数据丰富、衰减慢、传播距离远,利用气枪数据可以研究更大范围的地壳介质结构。

This article analyzes the waveform and frequency characteristics of the singles triggered by air-gun excitation and equivalent natural earthquake by S-transform.We stack the signals of other stations and analyze the propagation distance of air-gun signals after linear stacking and phase-weighted stacking based on clustering analysis to the reference station.The results show that:(1)the dominant frequency of air-gun signal is 3-6 Hz,and the station with distance of 151 km can receive the signal and its attenuation is slow.While the dominant frequency of equivalent natural earthquake is higher than air-gun signals,it is 10-20Hz with distance of 7.7km.Its propagation distance reaches 60km and its attenuation is faster.(2)After stacking the same number of signals about 2000 times by linear stacking and phase weighted stacking,the stations with distance of 225km and 350km can receive the air-gun signals.Compared with the signals from natural earthquakes,the signals of the air-gun are rich,the attenuation is slow and the propagation distance is far.Applying airgun source can study a wider range of crustal medium structures.