曹妃甸地震台网天然地震与人工爆破时频分析

搜集2014—2015年曹妃甸测震台网记录的各类爆破与天然地震事件,基于Matlab软件,编制程序实现短时傅里叶变换,对比分析核爆炸、化学爆炸、矿爆炸与天然地震的特征,分析频率随时间的变化规律。研究结果表明,天然地震与爆破在频率范围、频率分布和时频聚集性等方面具有各自特点,主要表现在:天然地震的时频图"多峰"且复杂,频率分布范围更广,频率成分集中在S波段;人工爆破的时频图"少峰"且简单,频率范围较窄,频率成分集中在P波段。本文的研究成果能够为今后区分天然地震和爆破提供依据。

Time frequency analysis of earthquakes and explosions recorded by Caofeidian Seismic Network

Based on Matlab software, we developed a program to achieve the short time Fourier transforms. We collected all kinds of seismic blasting and natural seismic events that recorded by Caofeidian Seismic Network from 2014 to 2015. Using time frequency analysis method, the nuclear explosions, mine explosions, chemical explosions and natural earthquakes that were recorded by Caofeidian Seismic Network are studied. The instantaneous frequency is calculate. Research results show that natural earthquakes and blasting have their own characteristics in frequency range, frequency distribution and time frequency aggregation. Time frequency map of natural earthquake is multimodal, the frequency distribution is wider, and frequency components gather in S band. The time-frequency map of the artificial blasting is less peak and simple, the frequency range is narrow, and the frequency components gather in P band. This study provides a basis for distinguishing natural earthquakes and explosions in the future.