The Earthquake Data Processing System

Natural seismic observation data is an important resource for studying the internal structure of the earth.Natural seismic data include abundant information reflecting the internal structure of the earth,which provides valuable scientific basis for human understanding of the earth and studying the earth.After continuous discussion and improvement in 1991,Kennett and Engdahl established the IASP91 model on the basis of the PREM model.With the rapid development of computer technology and the continuous emergence of massive natural seismic data,processing seismic data by computer technology has become an indispensable method.Based on IASP91 earth velocity model,a system software for processing natural seismic data is designed.The visualization data processing of natural seismic records was designed and realized by Intel Fortran platform.This system reads and processes the wide-band seismic data collected from the field station,mainly including the functions of signal reading and importing,preprocessing,seismic phase recognition and cross-correlation picking.On the basis of deep research,the program realizes that the reading time of the original seismic data is 24 hours.The data can be perfectly mapped out in the main window by normalization,and the jump waveform is used to draw quickly,which greatly saves the drawing time.According to the need,the variable area diagram and true amplitude waveform diagram can be drawn by setting.In order to suppress the interference caused by the external environment and processing methods,the filter design,time correction and bad track elimination of seismic data are realized.Different formats of seismic data files are merged and transformed.By using IASP91 earth velocity model,the travel time of seismic wave is calculated according to ray tracing programming,and the travel time law of partial seismic phase can be obtained,it is found that the simulation results of forward walking of each seismic phase are in good agreement with the travel schedule of corresponding seismic waves calculated by Australian seismologist B.L.N.Bennett,and the calculated speed can be guaranteed.After the seismic phase identification is correct,the cross-correlation technique can be used to pick up the time,greatly improve the picking accuracy,the cross-correlation data can clearly reflect the quality of each station waveform,reduce the error of qualitative analysis,through the system interactive picking work in the cross-correlation evaluation system in a good effect.All the software development results of this system are based on the Inter Fortran system,and easy to install,if the need to adjust the optimization code recompile can be directly run in the Windows system.In the procedure of seismic data processing,this system continuously improves the deficiencies and gradually improves and strengthens the functions,making the processing of data more simple,convenient and fast.Moreover,it has handled more than 1,000 large seismic events received from the station from 2013 to 2018.The practical application shows that the human-computer interaction system is simple to operate,accurate,fast,flexible and convenient,and is an effective tool for processing natural seismic data.