【摘要】 基于坚固体孕震模式 ,参考板内地震孕育特征和华北地区的地质构造特征 ,建立了 4层地壳结构模型 ,对近地表形变场和应力场的时空分布特征进行了动态模拟研究 .结果表明 ,在地震孕育的中长期阶段 ,坚固体近地表部位的形变相对稳定 ,出现形变空区 .在孕震的中短期阶段 ,坚固体近地表部位的形变出现快速增长的态势 ,平均应力明显增强 ,这是各种前兆异常出现有规律的迁移变化 ,即从外围地区逐渐向强震震源区迁移、集中的内在机理 .更多还原

【Abstract】 On the basis of the hard inclusion earthquake preparation model (HEPM for short) and referring intraplate earthquake preparation characteristics and geologic structure feature of North China,model of crustal structure of four layers with a hard inclusion,a soft inclusion and a vertical fault is constructed. Dynamic simulation on the space time distribution of deformation and stress fields near surface for the model is carried out. The results show that at beginning of earthquake preparation, deformation near surface of the hard inclusion in the model is relatively stable, a deformation gap is showed. During the medium short term period before earthquake, the deformation increased swiftly. Meanwhile, the average stress in the region strengthened obviously,which is the inner mechanism for migration of precursory anomalies with regularity from outer area to epicenter area of strong earthquake.更多还原