华北地区小震综合断层面解的模糊聚类分析

由微震P波初动方向资料,测定了华北地区(112——122E,35——41N)1981——1983年9月,16个综合断层面解。根据各解应力轴方向分布的不均匀性,对最大、最小和中等主应力轴方位进行模糊聚类分析,得到了各解间动态性的聚类谱系图.截取隶属度大于0.93的样本划分成四类,分析了各类方向特征,并讨论了地质构造与应力场及地震活动的关系. 

FUZZY CLUSTER ANALYSIS OF COMPOSITE FAULT PLANE SOLUTIONS OF SMALL EARTHQUAKES THAT OCCURRED IN NORTH CHINA

Composite fault plane solutions of earthquakes between January 1981 and September 1983 in the North China area (35-41N, 112-122 E) are determined by the data of first motion direction of P wave of macroearthqukes. According to the inhomogeneity of the distribution of stress axis directions of various solutions, the fuzzy cluster analysis is made for the directions of maximum, minimum and medium principal stress axes and a map of dynamic cluster spectral system of various solutions is obtained. Cut samples with subordinate degree of greater than 0.93 and divide them into 4 types. The characteristics of various types of directions are analyzed and the relationship between geologic structure and stress field and seismicity is discussed.