吉林省中部地区现今构造活动及现代地壳应力场特征的探讨

RESEARCH ON THE CHARACTERISTICS OF CONTEMPORARY CRUSTAL STRESS FIELD AND RECENT TECTONIC ACTIVITY IN CENTRAL AREA OF JILIN PROVINCE

采用单台小震综合断层面解方法 ,收集了长春台、丰满台、四平台、磐石台、通化台及敦化台6个台站自 1 990年以来所记录到的大量小震及其P波初动资料 ,求得了各台站所在区域范围内在该时段的区域应力场特征。结果表明 ,上述各区域普遍存在着以主压应力轴以NE NEE向 ,主张力轴以NW NNW向为特点的区域应力场。该特征与东北及华北区域地壳应力场的结果基本一致 ,说明该局部小区域应力场受到大区域应力场的控制 。

Based on a large number of small earthquakes and first motion data from 6 seismic stations (CHANGCHUN,FENGMIAN,SIPING,PANSHI, TONGHUA and DUNHUA) since 1990, the regional stress field features within the area of each seismic station in the period above were given by the method of compositive fault plane solution of small earthquakes for single seismic station. The result indicates that the principal compressional stress axes are NE～NEE direction and the principal extensional stress axes are NW～NNW in direction in every station area. This characteristic is consistent with that of the North and the Northeast China seismic region, which suggests that the activities of small local regional stress fields is controlled by a large one.