A Study Of Inversion Of Large Earthquake Repture Based On Fisher Linear Identification Methods

After decades of development,earthquake early warning technology becomes one of the important means of protecting against and mitigating earthquake disasters,but realtime large earthquake inversion research is still insufficient.Large earthquake fault of the traditional inversion method mostly based on the far field data,it gave accurate results in the hours after the quake generally,took too long time to meet the needs of the earthquake early warning.Real-time large earthquake inversion,can update warning target area range in real time,carry out emergency rescue effectively,this article based on the strong motion acceleration records,Fisher linear discriminant theory is applied to the rapid inversion of large earthquake fault in our country for the first time to classify seismic stations in real time.Calculate fault in projection scale on the surface of the earth through the distribution area of the near source stations in real time.This method does not need calculate seismic data when the reception is completed,it can reduce the waste of time in the process of data reception effectively.The main contents include:(1)Analysis five typical earthquake(Chi-Chi earthquake,Wen-Chuan earthquake,Jing-Gu earthquake,Ya-An earthquake,Lu-Dian earthquake)of magnitude greater than 6.5 based on Fisher linear discriminant theory,points out that the combination of vertical to the PGA and level to the synthesis of linear discriminant of PGV can be effective to classify stations,put forward suitable linear discriminant function to classify stations in real time in our country,seismic stations can be divided into two categories in real time by calculating linear discriminant function values of each station every second,the near source stations and far source station.(2)Apply the linear discriminant function to the criterion of seismic stations,calculate the linear discriminant function values of each station every second to classify stations,Linear interpolation according to the discriminant linear discriminant function value of near source stations in real time,approximate calculate the rupture scale of the projection on the surface of the earth from the earthquake happen to the current time,selects the projection region on the surface of earth automatically.The area of Interpolation calculation linear discriminant function values greater than or equal to zero approximate representative the projection area of fault on the surface.(3)Real-time inverse faults of Chi-Chi and Wen-Chuan earthquake using this method.the results show that the method in this paper can inverse the area of fault rupture on the earth's surface in a shorter period of time compares with others inversion results,prove that this method meet the requirements of earthquake early warning system for timeliness,The method accuracy has improved compared with the inversion fault method of traditional point source model,and the fault inversion results are basically consistent with internationally recognized.The performance of fault zone has a certain direction in this paper,It can strength the research of fast determine the strike of the fault in the future.