China Earthquake Focal Mechanism Solution Database Construction

The relative movement of the earth’s interior material may cause the rupture of the crustal rock strata,which promotes the development and activity of fault.Fault and earthquake are closely related.The movement of fault causes earthquake.Furthermore the occurrence of earthquake will promote the generation and development of new fault as well.Therefore,the study of the occurrence for an earthquake is to do research of the process of the fault’s rupture.Then,the geometric movement parameter for describing this process is called fault mechanism solution.Fault mechanism solution,which is also known as fault plane mechanism,is an important method to determine the nodal plane orientation,dip,sliding direction of the fault and to explore the rock mass dislocation at the focus of the earthquake and the process of the fracture.The distribution of historical focal mechanisms is scattered and the early data expression is not standardized.Nowadays,there is no complete,centralized and standardized historical focal mechanism solution database in China,which brings inconvenience to researchers in the analysis of earthquake sequence trend,analysis of regional tectonic stress field and determination of strong earthquake urgency ect.To this end,the main research goal of this paper is to standardize,unify,convenient,and comprehensive the current scattered and chaotic historical focal mechanism.After finishing,use Python tornado to establish a domestic open and most complete focal mechanism solution database platform.At the end of the article,in order to detect the volume and usability of the data,this paper makes a simple spatiotemporal analysis of the data in the database and compares and analyzes the data with other databases such as the Fundamental database of crustal stress environment in continental China and Global Centroid-Moment-Tensor.According to the division principle of the world stress map,the mechanism data is used to analyze the source type,and the regional characteristics of the focal mechanism solution and the characteristics of the regional stress field are analyzed one by one in combination with the active land.The figure shows that the data in this database is highly consistent with the Chinese regional stress map provided by the China Institute of Environmental Crustal Stress and the World Stress Map.