唐山地震前地倾斜矢量椭圆异常的研究
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摘要
研究了1976年唐山Ms7．8级地震前后北京地区和太原、张家口台连续五年以上的地倾斜资料和1991年内蒙敖仑布鲁格苏木Ms5．5级地震前后，石拐和呼和浩特地震台连续七年的地倾斜资料。发现年变矢量椭圆长轴在直角坐标系的分布，正常年份是集中且稳定的，即过原点在某两个象限中分布；而在强震前三年内，将发生大幅度转向。这种在确定的区域内，具有准同步性特点的异常群，可做为中强以上地震的一种中期前兆异常。
This paper has studied the ground tilt data of Beijing region, Taiyuan and Zhangjiakou stations in 5years before and after the Tangshan Ms 7. 8 earthquake in 1976, and the ground tilt data of ShigUai and Huhehot seismic stations in 7 years before an f after the Anlunbulugesumu Ms 5. 5 earthquakes in 1991.It is found that the distridution of the ellipse long axis of the annual variational vector in right angle coordinate is concentrated and stable in normal years, that is, passing initial POint and distributing in two quadrants, it will divert with large amplitude within three years before strong earthquake. These anomalies group with quasi -- s ynchronizat ion cha racteristics in a de fined region c an be u sed as a mid term precusory anomaly for moderately strong earthquakes.Subjectwords: ground tilt observation ; seismic precursor ; Tangshan earthquake
This paper has studied the ground tilt data of Beijing region, Taiyuan and Zhangjiakou stations in 5years before and after the Tangshan Ms 7. 8 earthquake in 1976, and the ground tilt data of ShigUai and Huhehot seismic stations in 7 years before an f after the Anlunbulugesumu Ms 5. 5 earthquakes in 1991.It is found that the distridution of the ellipse long axis of the annual variational vector in right angle coordinate is concentrated and stable in normal years, that is, passing initial POint and distributing in two quadrants, it will divert with large amplitude within three years before strong earthquake. These anomalies group with quasi -- s ynchronizat ion cha racteristics in a de fined region c an be u sed as a mid term precusory anomaly for moderately strong earthquakes.Subjectwords: ground tilt observation ; seismic precursor ; Tangshan earthquake
引文
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