南北地震带区域形变异常特征与地震关系研究

利用南北地震带及附近地区20世纪70年代以来的区域水准网和90年代以来的GPS监测网资料, 结合地质构造和监测区发生的多次6级左右及以上震例, 分析了震前区域性形变场异常的基本特征。 进而根据资料支持程度, 分别以GPS、 区域水准观测位移为地表约束, 以“973”项目活动地块划分结果为地质依据, 进行非震负位错模型反演计算, 研究了数值模拟结果反映的活动块体和边界断裂构造变形状态与地震的关系。 在此基础上, 定性与定量相结合分析研究了强震前区域性水平、 垂直构造形变异常特征及可能的机理, 初步总结了基于区域水准、 GPS观测与数值模拟的强震前区域构造形变异常的一些判据。

Study on the relation of regional deformation anomaly characteristics and earthquakes along South-North seismic belt

Using the data of regional leveling network since 1970s and GPS monitoring network since 1990s along the South-North seismic belt and vicinity, combining with geologic structure and recently occurred earthquakes (M_S≥6.0) in this monitoring area, the basic characteristics of regional deformation anomaly before earthquakes are analyzed. Then, depending on the supporting degree of data, under constraint of GPS or regional leveling observation displacement, and according to division of active massif of "973" project as geological basis, the inversion computation of aseismic negative dislocation model is carried out. The relation between deformation state of active massif and boundary fault structure reflected by numerical simulation results and seismicity is studied. Based on this, the anomaly characteristics and possible mechanism of regional horizontal and vertical tectonic deformation are qualitatively and horizontal and vertical tectonic deformation are qualitatively and quantitive studied. Some criteria of regional tectonic deformation anomalies before strong earthquakes are preliminary summarized on the basis of regional leveling, GPS observation and numerical simulation.