Application Research On Earthquake Prediction Method Of "Source-line Model"

Source-line model is model based on the intersection of two long characteristic lines associated with seismic source to predict the location of strong earthquake,the first characteristic line is the maximum shear stress line with 45 angle to the regional principal compressive stress with the most distribution of precursory information,and the second characteristic line is the precursor co-migration line,which is defined as the line composed of earthquake-earthquake migration or precursor-earthquake migration in history.When the model was put forward,the Haicheng earthquake in1975,Tangshan earthquake in 1976 and Wenchuan earthquake in 2008 were analyzed based on precursor-earthquake migration.This paper starts from the less study of earthquake-earthquake migration,the earthquake prediction method of source line model is supplemented by the earthquake migration phenomenon.This paper studies the seismic migration phenomena or seismic activity correlation phenomena between the western part of the Altyn Tagh fault and north-south seismic belt in the Tibetan plateau since twentieth Century,based on the occurring time of earthquakes with M_S?6.0 at the western part of the Altyn Tagh fault,the seismicity of M_S?5.0 in the north-south seismic belt after the earthquake in the western part of the Altyn Tagh fault is studied at different time intervals.The study shows that there is a certain correlation between the moderate strong earthquakes in the north-south seismic belt and the earthquakes in the western of the Altyn Tagh fault.The three major earthquakes occurred in the north-south seismic belt all occurred after the corresponding earthquake in the western part of the Altyn Tagh fault.Within one year after the earthquake in the western part of the Altyn Tagh fault,there will be37.5%probability of 7.0-7.9 earthquake in the north-south seismic belt,23.6%probability of 6.0-6.9 earthquake,and 28.6%probability of 5.0-5.9 earthquake.The Pattern informatics algorithm is used to verify the correlation between the seismicity of the two areas,the results show that only Yutian earthquake with M_S 7.3 and Wenchuan earthquake with M_S8.0 in 2008 have good prediction results.Based on the migration phenomenon of earthquakes or the correlation phenomenon of seismicity,combined with the distribution of pre-seismic anomalous,the associated earthquakes occurred in the north-south seismic belt since 2000 are analyzed.It is found that the relationship between the distribution of anomalous points and the location of epicenter is different in different areas of the north-south seismic belt.Most of the anomalous points in the north section of the north-south seismic belt are concentrated on one side of the epicenter,the anomalous points in the middle section are divided into two parts distributed on both sides of the seismogenic fault and the epicenter is easy to form a large abnormal blank area,the distribution range of abnormal points in the south section is wide.On the basis of the source-line model,the method of earthquake prediction by using the correlation phenomenon of seismicity is supplemented.That is,after the earthquake with M_S?6.0 in the western part of the Altyn Tagh fault,the abnormal points in the north-south seismic belt are counted and drawed.If the distribution of abnormal points in a certain area forms an abnormal blank area,it can be determined that the area is a seismogenic body.It is predicted that there will be at least one M_S?6.0 earthquake within one year after the earthquake with M_S?6.0 in the western of the Altyn Tagh fault.