b Values Spatial Distribution Characteristics of the Main Active Faults in Southwestern Yunnan
Xie Zhuojuan
Li Shanyou
LYuejun
Abstract：Southwestern Yunnan is located in the southeast edge of the Tibetan plateau,is one of strong continental tectonic ac-tivities and frequent earthquake area in our country.In this paper,based on the principle of negative correlation between region-al seismic b-value and crust internal stress distribution,we made the b values map by the maximum likelihood method and combined with the feature of regional seism tectonic background and active faults,analysis spatial difference of distribution b values along the fault belt,reflect the level of stress accumulation and activity habits in the different fault belt and the same fault different section,which reflects the spatial difference of seismic risk.The research result shows that the b value of the study area is 0.3 to 1.2,the average value of b is 0.576,δb is 0.046;the distribution b value and different sections in the Fault belt and fracture belt are uneven.The southern section of the LANCANG river fault,NU river fault etc in the low b value area of the study area,it suggests that this region is at a relatively high stress state and the possibility of strong earthquake in the future.On the contrary,Ailaoshan fault belt、the eastern and western section of the Longling-Ruili fault belt etc.in the high b value area of the study area,it suggests that this region is at a relatively low stress state and the possibility of small earthquake in the next few years.The researching methods of this article and its conclusion are available for risk evaluation research and long-term seismicity prediction research as a reference.
Keywords：southwestern Yunnanspatial distribution of b valuesseismic hazardfault
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：12( 1755-1766 )