关中地区断层形变异常与地震活动的关系

The relationship of the fault deformation anomaly and earthquakes activity in Guanzhong area

基于关中地区近20年的跨断层垂直形变资料,采用速率和异常强度模型对断层形变异常进行分析,进而研究关中地区地震与邻近构造带强震活动关系。结果显示:从断层活动速率、映震能力及异常强度分析,秦岭北麓断裂和麻街测站垂直活动大幅度剧烈,对三次强震及同震形变都有很好地反映,应对这两个区域地震危险性予以重视;形变异常强度大于等于0.55,时间上表现为中短期异常时,关中地区及相关联的构造带上一般有地震发生,可作为预测地震的指标之一;在1997—2010年,关中地区断层活动呈同步分时段的异常特征,与这一时期青藏高原第三次地震活动丛集高潮期符合,可能是西部地区地震活动的重要标志之一。

Based on the cross-fault vertical deformation materials in Guanzhong area in the past 20 years,using velocity and anomaly intensity models to analyze the fault deformation anomaly,and study the relationship between earthquakes in the Guanzhong area and strong earthquakes in the adjacent tectonic zones.The results showed that from the analysis of the cross-fault activity rate,reflection ability and anomaly intensity,the Northern Piedmont of Qinling fault and Majie station was drastic and violent of the vertical movement,three strong earthquakes and co-seismic deformation were well reflected,and earthquake risk was taken seriously;the anomaly intensity of deformation was greater or equal to 0.55,and the time appears in the mid-short term anomaly,generally earthquakes occurrence in the Guanzhong area and associated tectonic belts,which could be used as an indicator of earthquakes prediction;During1997—2010,the fault activities presented anomalous characteristics of synchronous sub-periods in the Guanzhong area,which coincided with the third high-rise period of the seismic activity in the Qinghai-Tibet Plateau during this period,which may be one of the important signs of seismic activity in Western China.