台湾南投7.6级地震地下流体远场异常及其前兆意义

The Far-Field Anomalies of Underground Fluid for the Nantou Earatquake with Ms=7.6 in Taiwan,China and Their Precursor Implication

深入分析了 1999年 9月 2 1日 0 1时 47分台湾南投 (2 3°42′N ,12 1°0 6′E) 7 6级地震时浙江省地下流体观测井出现的显著中、短期前兆异常。异常出现时间早 ,持续时间长 ,阶段性变化明显 ,特征明显 ,易于识别 ,与本区 (震中距≤ 40 0km)地震前兆异常有明显的区别 ,是具有预测意义的地震前兆异常。震中距约 70 0km左右 ,微动态异常基本没有显示 。

Remarkable medium and short term precursor anomalies appeared in the observation wells for underground fluid in Zhejiang before the Ms=7 6 Nantou earthquake in Taiwan(23°42′N,121°06′E)at 01∶47 am on September 21,1999 are analyzed deeply.The anomalies which occurred early with a long duration,clear phase variation and distinct features differed from the seismic precusor anomalies in the Zhejiang region(epicentral distance≤400km),have prediction signification and belonged to field-precursor anomalies.