震前兆信息传播、分布及其探测原理

地壳岩石层由板块、断层和其间的断层泥构成,在研究地震前兆信息传播这类准静力学问题时,应将其作为大尺度离散态颗粒物质体系处理.地震孕育过程中,在大地构造力驱动下,岩石层块克服所受摩擦力和边界断层泥阻力发生滞滑移动.当岩块间断层泥受挤压后其强度增大到一定程度时,又推动下一岩石层块滞滑移动,就这样渐次使其他岩石层块发生移动,并以力链形式分布和传递.文章给出了此模型的物理依据和实际观测例证;通过模拟实验和分析阐述了力-移动-形变在地层中分布的表达形式和传播时间序;说明了地震前兆信息的主要特征及其与地震发生之间的关联,以及探测有效地震前兆信息的方法原理.同时,论述了用颗粒物理原理与连续介质观念对地震前兆认识的本质区别,解释了连续介质观点难以理解的若干地震学问题. 关键词： 地震前兆 颗粒物质 滞滑移动 力链

Propagation, distribution and detection principle of seismic precursory signals

The earth crust consists of tectonic plates, faults and the fault gouges at their boundaries. In the case of studying such an issue as quasi-static mechanics on the seismic precursory spreading, the crustal lithosphere must be treated as a granular system consisting of large-scale discrete grains. In the process of seismogeny, the rock blocks driven by tectonic forces induce a stick-slip motion by overcoming the friction and the boundary resistance. When the fault gouges between blocks are squeezed and their strength increases to a certain degree, the next block will be pushed to generate a stick-slip motion and the successive rock blocks move gradually in the same way. As in any granular system, the distribution and transfer of force and the movement of the rock blocks must be in the chain-like form. This model is not only reasonably deduced from the physical bases, but also supported by many actual observations. In this work the distribution of force-motion-deformation and the spreading time sequence are given with the simulated experiments and analysis. The main feature of the generated precursory information is described. The essential difference between the understanding of seismic precursor led by viewing the crustal lithosphere as granular system and that as continuum medium is presented. How to acquire effective seismic precursory information as well as how to associate it with the occurrence of earthquake is discussed. Some of the seismology problems are explained reasonably, which can be hardly understood from the continuum medium view point.