摘要
1998年 1月 1 0日在河北省张北县和尚义县之间 (41°0 6′N,1 1 4°1 8′E)发生 6.2级地震 ,震源深度为 1 0 km。震前一二年发现有明显的地震前兆异常 :4级地震条带明显 ,区域地震活动增强并出现低 b值异常等 ;震前数天至数月有赤城、张家口地倾斜异常 ,阳原、宝昌地电阻率异常 ,延庆地下水位异常 ,呼和浩特、北京地磁 ,地磁低点位移以及热红外等前兆异常。中、短期地震前兆较丰富 ,临震前兆异常不够明显。1 997、1 998年初北京西北至晋、冀、内蒙古交界地区被列为可能发生 5～ 6级地震重点危险区。张北 6.2级地震虽然有较好的年度中期预报 ,但没有作出临震 (几天内 )
An earthquake with MS=6.2 took place between Zhangbei and Shangyi counties, Hebei province on January1 0 ,1 998.The epicenter is located in the area of4 1°0 6′ N,1 1 4° 8′ E,with the focal depth of1 0 km.The obvious earthquake precursory appeared2 years ago:a significantseismic beltemerged with earthquakes with M≥ 4 ,regional seismic ac- tivity increased andbvalue became lower than before.Several days to several months be- fore the main shock,the precursors were also found,such as ground tilt in Chicheng and Zhangjiakou,geoelectric resistivity in Yangyuan and Baochang,water level in Yangqing, geomagnetic field and low-pointdisplacement in Hohhotand Beijing,thermal infrared im- age in North China,etc.There are more medium-and short-term precursors,but fewer imminent earthquake precursors. The boundary region of Shanxi Province,Hebei Province and Inner Mongolia,includ- ing Zhangbei county,has been listed as a special risk region for earthquake with M =5～ 6 since early1 997.In spite of having a clear yearly medium-term prediction,the imminent earthquake prediction failed.
出处
《地震》
CSCD
北大核心
1998年第3期211-218,共8页
Earthquake
基金
国家地震局"九五"科研攻关项目!( 95-0 4 -0 1 -0 2 -0 1 )
关键词
地震预报
地震前兆异常
地震重点危险区
震级
Earthquake Prediction,Seismic precursory anomaly,special risk region for earthquakes,Zhangbei MS6.2 earthquake
