基于高温高压岩石破裂实验结果对中强地震前震中附近区域部分地震学现象的初步解释

PRIMARY EXPLANATION ON SOME SEISMIC PHENOMENA AROUND THE EPICENTER AREA BEFORE STRONG AND MODERATE EARTHQUAKE BASED ON THE HT-HP ROCK FAILURE EXPERIMENTAL RESULTS

依据高温高压岩石破裂实验结果并结合理论分析 ,对震中附近区域不同深度温压条件下岩石变形破坏性质及破坏失稳的力学行为进行了研究 ,在一次应力加载循环中 ,发生破坏的部位随时间具有向深部下迁的趋势 .考虑到深度温压条件下岩石的渐进式破坏行为及突发失稳 ,对主震前震中附近区域小地震活动的增强、平静、活化等现象 ,以及b值等时间序列参数变化的可能机理进行初步探讨 。

Based on the model from HT-HP rock experimental result and theoretical analysis,for epicenter area of strong and moderate earthquake,the properties and mechanical behaviors of rock deformation and failure under the condition of different temperature and pressure are studied.According to the model, during a loading circle, the small earthquakes move to the deeper crust gradually with the tectonic stress increases. The relocation results of some earthquake sequences support this concept model.Considering the mechanical behaviors of rock incremental failure and abrupt instability, the enhancement and quiescence phenomena of seismic activity before middle and strong earthquake, as well as the changing characteristics of b value are studied primarily. The potential mechanism of two kinds of quiescence and change of b value are discussed.