强矿震地球物理过程及短临阶段预测的研究

STUDY ON GEOPHYSICAL PROCESS OF STRONG TREMOR AND FORECASTING IN THE SHORT-TERM AND IMPENDING STAGES

用区域强震震源机制解、现场地应力测量、三维有限差分数值模拟方法分析强矿震的孕震环境;通过定量观察采矿与矿震活动的相关性,分析强矿震的诱发原因;基于中尺度地震实验场高密度数字地震和前兆台网的现场观测,用地震学方法和小波工具分析强矿震孕震过程采集到的数据,提取短临阶段的异常信息;通过强矿震的震源机制解判断震源处的应力释放状态。提出地质构造环境、地应力场和采矿活动共同作用诱发强矿震的机理和次生应力场在孕育该震过程起主导作用的观点,发现震前短临阶段存在可信的b值、η值、频次、波速比等地震学异常和定点潮汐形变前兆异常,对异常信息的提取方法和强矿震短临阶段的预测进行了探讨。

By means of focus mechanism solution of regional strong earthquake, spot geostress measurement and 3D finite difference numerical simulation analysis, analyze seismogenic conditions of strong tremor. With the help of quantitative observation of relativity between mining activity and tremor, analyze induced factor of tremor. Based on field observation of high density digital seismograph and tidal deformation network of meso-scale seismological experimental sit, analyze the data of strong tremor process with seismological methods and wavelet tools, extract anomalous information of strong tremor in the short-term and impending stages. Make use of focus mechanism solution of stronger tremor, judge stress release state in focus. Bring forward the mechanism that geological structure environment, geostress field and mining activity work together to induce tremor and the viewpoint that secondary stress field play an important role in seismogenic process. Believable b value, η value, frequency, Vp/Vs ratio seismological anomalies and fixed point tidal deformation anomalies are found before strong tremor in the short-term and impending stages. Extract methods of anomalous information and forecast of strong tremor in the short-term and impending stages are discussed.