张北6.2级地震中短期阶段异常演化及同步性
EVOLUTION AND SYNCHRONISM OF THE MEDIUM AND SHORT TERM ANOMALIES BEFORE ZHANGBEI M6.2 EARTHQUAKE
-
摘要: 基于强震前主破裂潜在变化过程中产生的地壳形变异常及伴随地壳形变而产生的地下水化学前兆现象随时间变化显示出的动态异常,依据怀来地震台地形变、流体观测资料,研究了1998年张北6.2级地震前地形变、地下流体异常特性及同步性,有由短期向临震演化的不同阶段异常特征。形变异常早于流体异常出现,临震异常集中出现,反映明显。断层气CO2、水汞、体应变同时在震前的二个月出现,显示出异常的集中性、同步性特征。Abstract: the characteristics and synchronism of the crustal deformation and subsurface fluid anomalies observed by Huailai Seismostation before Zhangbei M6.2 earthquake in 1998 are studied. Evolution of the anomalies from short term to imminent period shows phasic feature: crustal deformation anomalies appear earlier than fluid anomalies; imminent anomalies appear concentratively. That CO2, water Hg and cubic strain anomalies appear two month before the earthquake shows the synchronism of the anomalies.