Analysis Of Seismic Intensive Features In Kunming, Yunnan Province

The study of seismic activity is the work of finding the relation between the base data,such as the data of space,time and magnitude from seismic observation system(such as seismic network)or historical record.The spatial-temporal distribution of seismic events are extremely inhomogeneous.In some places the activity of earthquake is strong,while in other places the seismic activity is very weak.Therefore,through the analysis of seismic activity characteristics,we can understand the basic laws of seismic activity,and then analysis the law of strong earthquake.The damages caused by the earthquake are catastrophic,which makes the study of seismic activity of vital importance in the analysis of seismic hazard and the determination of historical seismic events.Many researchers have used a variety of methods to study seismic activity.According to the character of the research method,the seismic activity research can be divided into qualitative research method and quantitative research method of seismic activity.Among the research methods,the “calculation of seismic density”method is an effective method to analyze the seismic activity characteristics.This method has been applied to the of seismic activity in North China after years of improvement.(Wang Jian,1976;Wang Jian,et al.,2004;Wang Jian,et al.,2004;Wang Jian,2007),and achieved remarkable results.the “calculation of seismic density” method calculates the seismic density Vj of the regional grid node and divides the research area into the seismic density zones.After studying the detailed spatial-temporal distribution of the zones,the method can further analyze the type and cause of them,which will help us make an understanding of the seismic activity characteristics of the whole study area.In addition,the relationship between seismic density and the parameters of strong historical earthquakes is also discussed.The emendation of the epicenter of the 1833 M8 earthquake and the possibility of missing seismic events in research area were suggested.This paper also proposes a method of seismic dense scanning in order to give a more clear understanding of the dynamic characteristics of seismic density over time.Based on the analysis of the information provided by this method,we find that the dynamic evolution characteristics of earthquake density with time are similar to "diffusion",which is defined as "seismic density diffusion".By studying the relationship between density and ending time,we have found that the "seismic density diffusion" has a certain direction.In addition,this paper also analyzes the changes of density before and after strong earthquakes,and points out that there might be seismic density background before the occurrence of ML6.0 strong earthquakes.Finally,this paper discusses the combination of HypoDD method and he“calculation of seismic density” method.However,due to quantity of the data,the relationship between them in improving the accuracy remains further discussion.