短临前兆跟踪中的前兆场反演法和地震参数预报

利用静力位错理论对地震发生过程中的应力场状态进行分析;利用震时被灵敏仪器记录到的高分辨率应变(形变)阶的量值及其空间分布来反演地震断层的参数。将大地形变仪器的观测数据进行统一标度的归化,对前兆观测物理量进行归化处理分析,并进行震例验算。为正确把握地震时震源周边岩石中的应力过程及对在岩石中设置的形变类仪器的影响情况,特选择在布有各类高灵敏形变观测仪器的徐州综合形变地震台大型坑道中,使用化学致裂试验模拟震源的致裂点周围不同构造和距离位置上的岩石应力状态,分析应变的衰减规律,研究岩石中的不同构造方向上与距离因素有关的能量释放情况,建立相应的关系式。编制了震源参数反演、前兆场物理量归化处理等计算软件。通过震时形变资料反演地震断层参数,在为探索地震预报新途径方面做了一些尝试。

Inversion Method of Precusor-field of Deformation in Tracing Short-term Precusor and Earthquake Parameter Prediction

Inversion for focal parameters is a method of analysing the focal body. In the instant of an earthquake occurring, a coseismic deformation step can be recorded by automatic deformation observation equipment with high sensitivity, by which the earthquake fault parameters can be inverted applying certain fault dislocation model. Before an earthquake, the degree of order of crustal deformation increases apparently with temporal and spatial anomalies of deformation field. According to the correlation between the anomalies and the coseismic deformation step, the focal parameters can be inverted by precusor field data of deformation before the earthquake, on which the research of earthquake prediction can be carried out. In order to predict earthquake by this means, the following problems are required to be solved: 1.the analysis and study of mechanical state of precusor field; 2. the study of nomalization of precusory observation data for inversion; 3. the selection and check of focal parameters model for inversion: 4. applying inverted focal parameters in earthquake prediction. To solve these four problems, by analyzing stress states in the process of an earthquake according to the theory of static dislocation source, the fault parameters of the earthquake are inverted by using high resolution strain data recorded by sensitive instruments during earthquake. Earthquake examples are calculated after geodetic deformation data and physical precusor data are scaled and normalized respectively. In order to understand the stress process in rock adjacent to earthquake hypocenter and its effects on deformation instruments installed in rock, a chemical fracturing test was carried out in a large tunnel of Xuzhou synthetic deformation station, where various types of defomation instruments with high sensitivity were installed, to simulate the stress state in different structure and distance in the vicinity of fracturing point. The decay law of strain was observed, which gave the relationship between released energy and distance in different tectonic direction. The software for hypocenter parameters inversion and precusor field data normalization were worked out. By inversion of deformation data during earthquake for seismic fault parameters, a new kind of earthquake prediction means is proposed and some progresses have been achieved.