Research On Real-time Prediction Method Of Seismic Instrument Intensity

Earthquake early warning is a new and effective way of earthquake hazards mitigation in recent twenty years.It can reduce the casualties and property losses by getting the earthquake information rapidly and releasing to the public during the time between earthquake happens and destructive earthquake waves come.For assessing the earthquake damage rapidly,more and more researchers calculate the seismic instrument intensity using the real-time earthquake waves.In order to predict the seismic instrument intensity using the initial information of P wave in the process of earthquake early warning,this paper puts forward two real-time continuous methods to predict the instrument intensity,and uses the models to test and analysis four earthquakes rely on different station networks.The contents are summarized as follows:(1)629 earthquakes were collected from KiK-net strong motion network during the year between 1999 and 2016.And we also used the strong motion records of Wenchuan earthquake in 2008,Chi-Chi earthquake in 1999,and Ludian earthquake in 2013.The pretreatment and selection was done to the strong motion records,and then we used the methods include STA/LTA and AIC to detect the P-wave automatically.We also extracted the source parameters and 7 ground motion parameters in 20 seconds from all selected stations after triggered,and calculated the final instrument intensity.(2)A continuous prediction method of earthquake instrument intensity has been developed based on the real-time PGA and PGV after the P-wave triggered.After the earthquake happens,the change of the instrument intensity follows some regularity.We use functions to describe the increase form of the intensity,and find out the relationship between the parameters in functions and source distance.The prediction result of this method was tested and improved.We used every second in 20 seconds after station triggered to predict the final intensity,and found three models.Finally,we tested three models and got reliable result.(3)A prediction method of earthquake instrument intensity has been developed based on artificial neural networks.We found the actual situation of getting information in earthquake early warning and built three effective models by using the information of P-wave triggered.The data in 20 seconds after the P-wave triggered was analyzed and suitable samples were chosen for the net training.The three models have different ranges of application and different prediction results.In general,the prediction results get better as time goes on from 1 to 20 seconds.(4)According to the methods developed in this paper,we tested the methods and predicted the intensity of 4 earthquakes rely on different station networks.Then we compared the prediction results of 11 typical stations and determine the application range of the models.Finally,we summarized the prediction methods of earthquake instrument intensity.