Joint Earthquake Source Process Inversion Method Of High-rate GPS And Seismographic Data Based On Genetic Algorithm

On observations of earthquakes,there are always new techniques.Since the last century90's GPS system was officially put into use,the researchers quickly applied in various fields.In the Middle time-scale and large region,GPS can provide displacement filed with approximate absolute datum,so it was quickly used in long-term crustal deformation monitoring,thus becoming important sources of seismic monitoring data in larger time-scale.In addition,continuously operating GNSS tracking stations or periodic observations can provide the coseismic displacements.High sampling rate(1HZ and above)GNSS receivers are now increasingly being installed near the earthquake zone of continuous tracking station,which can provide a lot of co-seismic near-field high-frequency GNSS data.If these data are used only to obtain the static co-seismic deformation,there will be a loss of time-domain information in the data.This paper proposed a method to inverse the rupture process of earthquake source with either near-or far-field waveform so that we can make use of the near-field GNSS-measured waveform.We search the rupture speed in a given range with certain step size.For each rupture speed,we get the uniform source time function of subfaults by Genetic algorithm,and get the slip distribution by linear method.Taking the LuShan M_W6.6 earthquake for instance,we made a numeric simulation that preliminarily verified the feasibility of our method.Finally we inversed the rupture process of LuShan M_W 6.6earthquake observed waveforms.The distribution of slips on the fault plane coincide with the existing researches,and the observed waveforms and synthesized waveforms fit well at some sites,but the result at some sites are not satisfactory,that verified the feasibility of the method proposed in this paper,yet there are still many details need to be improved.