Research And Analysis Of K-core Structure In Earthquake Network

In recent years,earthquakes happen frequently in the world,which becomes an important research object for researchers.Not only the seismologists,but also the researchers in different fields try to study the regularity of the occurrence of earthquakes.Due to the complex formation mechanism of earthquakes and the relationship among earthquakes,complex network is introduced into seismic study,which becomes a focus in earthquake filed now and gains some research results.In 2004,Abe first introduced complex network into the investigation of earthquake,proposing an earthquake network construction method based on time series.According to the insufficient of the network construction method based on time series,an earthquake network construction method based on time-space influence domain is put forward by our laboratory.The thesis has found that the earthquake network has the characteristics of small world and scale-free by verifying the earthquake network constructed by space-time influence domain,that is,the earthquake network represent a form of complex network.The way of k-core decomposition is used to simplify the network topology,which can describe the characteristics of the network that the degree distribution cannot describe,revealing the structural property and hierarchy property derived from the special structure of system.Then,the way of k-core decomposition is applied to the earthquake network.The results show that the coreness of nodes obey power-law distribution.The thesis mainly discusses the relationship between the highest core and the main quakes.It first introduces the great influence of highest core in the network and finds the nodes in the highest layer cluster together.Then,an important phenomenon is found that the main quakes tend to occur at the location where the nodes in the highest layer are are located by analyzing the seismic data in different regions.In addition,the energy of the highest core is the highest before a main quake.Next,the evolution of the coreness is analyzed before and after main shocks.The results show that the value of the coreness rapidly increase before a main quake,and reach the maximum when a main quake occur.At last,we analyze and predict the regularity of the network of China according to the relationship between main quake and the highest core.The thesis provides a new way for us to analyze and research the seismic system through the investigation of the relationship between the highest core and main quake.