遥感-岩石力学(I)——非连续组合断层破裂的热红外辐射规律及其构造地震前兆意义

以构造地震孕震机制之一即非连续组合断层破裂发震为模拟对象，利用双轴加载实验系统和红外热像仪，对雁列和同线非连通这两种非连续组合断层在双轴加载破裂失稳过程中的红外辐射特征进行了模拟实验研究。研究表明：双轴加载过程中岩石表面红外辐射温度的变化对应岩石应力变化，具有阶段性规律，包括初始、弹性、应力闭锁、解锁和屈服破裂5个阶段。自弹性阶段开始至解锁阶段，岩石表面的平均红外辐射温度(AIRT)的动态曲线表现为“上升-下降-再上升”的演变特征：而断层雁列区和非连通区在解锁阶段其热像出现高温异常条带，非连通区的高温异常条带还具有“增强-减弱(平静)-再增强”的演变特征。其地震前兆的时空意义为：(1)构造地震活动区卫星遥感AIRT的上升趋势可作为地震中期预警指标；(2)热像局部正异常条带预示未来震源位置；(3)AIRT下降与热像局部热异常条带的减弱(平静)一起，可作为构造地震的短临前兆。

REMOTE SENSING-ROCK MECHANICS ( I )--LAWS OF THERMAL INFRARED RADIATION FROM FRACTURING OF DISCONTINOUS JOINTED FAULTS AND ITS MEANINGS FOR TECTONIC EARTHQUAKE OMENS

The fracturing of discontinuous jointed faults is a mechanism of tectonic earthquake. By use of biaxial loading system and thermal infrared imaging system,the thermal infrared radiation features of two kinds of discontinuous jointed faults,en echelon faults and collinear disconnected faults,were experimentally studied in the process of loading and fracturing. It is revealed that the thermal infrared radiation of the surface of loaded samples is related to the load stress,and the variation stage can be classified into five stages including initial,elastic,stress blocking,stress deblocking and fracturing stage. From elastic stage to stress deblocking one,the dynamic curve of average infrared radiation temperature (AIRT) vs time is of the features of rising to dropping,and to rising again. During the stage of stress deblocking,positive infrared abnormity strip emerges in the discontinuous locations of en echelon faults and disconnected faults,and the positive infrared abnormity strip of disconnected faults is of the features of enhancing to weakening (or silence),and to enhancing again. Its important meanings for earthquake omens include that (1) the rise of AIRT curve of satellite infrared remote sensing for the seismic active region can be taken as the index for the middle-term forecast of structural earthquake,(2) the location of local positive infrared abnormity strip can be used to predict the location of hypocenter and (3) the dropping of AIRT curve together with the weakening (silence) of local positive infrared abnormity strip can be taken as the short-term prediction omen.