宁夏地区地震目录最小完整性震级分析

收集宁夏测震台网地震目录资料，采用MBS、EMR、震级-序号、MAXC、GFT等方法，对宁夏境内1970-2017年最小完整性震级M_c时序变化进行综合分析，确定采用EMR方法测定的M_c较为理想，并进一步分析该区M_c时空分布特征。结果显示，宁夏测震台网测震模拟观测、数字化改造及"十五"数字化运行阶段，M_c分别为M_L 2.2±0.1、M_L 1.7±0.1、M_L 1.6±0.1；"十五"数字化运行阶段以来，M_c空间分布不均匀，整体维持在M_L 1.3左右。

Research on minimum magnitude of completeness for earthquake catalogue in Ningxia region

Based on the collected earthquake catalogue and seismic network data of Ningxia Province, the variation of M_c for earthquake catalogue within the territory of Ningxia from 1970 to 2017 is analyzed synthetically in this paper using the various methods such as b-value stability approach (MBS), Entire Magnitude Range (EMR), magnitude-order number, the maximum curvature (MAXC) and the goodness-of-fit test (GFT). It shows that the method of EMR is fit for computing M_c in all kinds methods in Ningxia. The characteristics of spatial distribution is analyzed. The results showed that M_c is M_L 2.2 ±0.1, M_L1.7 ±0.1, M_L1.6 ±0.1 respectively in the stage of analogue observation, digitization observation and the tenth five-year plan. The spatial distribution of M_c since the "tenth five-year plan" is asymmetrical and the value of M_c is about M_L1.3.