与强地震有关的视电阻率各向异性变化  

Anisotropic changes in apparent resistivity associated with strong earthquakes

作　　者：杜学彬[1] 马占虎[1] 叶青[1] 谭大诚[1] 陈军营[1] 

机构地区：[1]中国地震局地震预测研究所兰州基地,兰州730000

出　　处：《地球物理学进展》2006年第1期93-100,共8页Progress in Geophysics

基　　金：国家自然基金项目(40474027);中国地震局地震联合基金项目(102058)资助

摘　　要：研究了27个强地震附近41个地电台的视电阻率变化，在震前1年尺度～短临阶段，在超过95％的台站上与震源机制解最大主压应力方位正交（或近于正交）测道的视电阻率变化最显著，主应力方位（或近于该方位）的测道的变化反之，其物理机理比较清晰．可以确认：在强地震孕育晚期阶段，在震源区及附近视电阻率各向异性变化是客观存在的地球物理现象，在震中区附近可观测之．Study the changes in apparent resistivity observed at 41 geo-electric stations near 27 strong earthquakes in China. The result shows that for over 95% stations the most prominent change recorded is in the survey line perpendicular or nearly perpendicular to the maximum compressional stress orientation of the focal mechanism solution while the smallest change is in or close to the orientation. The reason on the anisotropic changes is distinctly discussed. It is believed that the anisotropic changes are a kind of geophysical phenomena associated with the late preparation period Of strong earthquakes and can be indeed recorded near the epicentral region.

关 键 词：强地震 晚期阶段 视电阻率变化 各向异性 最大主压应力 

分 类 号：P315[天文地球—地震学] P319[天文地球—固体地球物理学]