天山地区地下水位动态前兆异常敏感点的初步分析(以新04井为例)

天山地区新04井是地下水动力学地震前兆的一个敏感点。观测事实表明,该井水位与地震活动有密切的关系。观测期间,在距该井150km范围内共发生4.0级以上地震24次,其中5.0级以上地震(未发生6.0级以上地震)5次,震前该井水位均出现了明显的下弯形异常变化。大多数4.0—4.8级地震前水位也有不同程度的异常反应。认为,特定的地质构造交汇部位、地热异常区和地下水动力差异不稳定带可能是该井水位动态灵敏反映区域地震活动的原因之一。

PRELIMINARY ANALYSIS OF SENSITIVE SITES OF GROUND WATER LEVEL FOR EARTHQUAKE PREDICTION IN TIAN SHAN REGION

Based on comparing anomalous variations of grounchvater level in multiple wells before some earthquakes and their geotectonic background,, hydrogeody-namic condition and geothermal environment near the wells, we consider that Xin-04 well is one of sensitive sites for the use. of observing groundwater level precursors in Tian Shan area. Since 1977, 24 earthquakes ( Ms^4.0 ) have occurred within a radius of 150km. Among them there are 19 earthquakes before which short-term anomalous variations of water level in the well appeared in different degrees, particularly before 5 earthquakes ( Ms>5.0 ) . It is considered that a special geotectonic cross place, a geothermal anomalous district, and a unstable belt of hydrodynamic state may be the main reasons of sensitively reflecting regional seismic activities in the well.