陕甘宁青地区的地形变特征与强震活动
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摘要
分析了陕甘宁青地区的地壳形变特征及其与强震的关系 ,结果表明 :(1)地壳形变特征存在时空差异性 ,不同地区地形变活动强弱与其至主要边界断裂带的距离存在相关性 ,主要边界断裂带附近地区相对活动强烈 ,远处则减弱。 (2 )不同时期各断层地形变活动强弱不同 ,既和构造应力场的变化有关 ,又与地震活动关系密切 ;断层垂直形变的逆继承性构造运动的活动时期远小于继承性构造运动的活动时期 ,且不同区域地壳构造运动发生转折的时间不尽相同 ,同时断层形变前兆异常亦存在时空差异性。 (3)多场地、大范围的断层活动异常可能与强震活动相呼应。
The features of crustal deformation and its relationship with strong seismic activity of the Shan-Gan-Ning-Qing area are analyzed.Through the analysis following results are given: ① the features of crustal deformation are different in time and space.There is correlation between the intensity of crustal deformation and distance of the site to the main boundary fault zone, it means that the deformation is strong in the area near thefanlt,or else the deformation is weak in the area far from the fault.②The intensity of crustal deformation in various fault and different period is different,which is related to the change of tectonic stress field and to the seismic activity as well.The active period of reverse successional tectonic movement of vertical fault deformation is much shorter than that of the successional one.The time, in which the turn of crustal tectonic movement occurs, is not quite identical in different regions and there is difference in time and space even for precursor anomalies of fault deformation.③ Multi-site and large scale faulting anomaly may echo each other with the strong seismic activity.
The features of crustal deformation and its relationship with strong seismic activity of the Shan-Gan-Ning-Qing area are analyzed.Through the analysis following results are given: ① the features of crustal deformation are different in time and space.There is correlation between the intensity of crustal deformation and distance of the site to the main boundary fault zone, it means that the deformation is strong in the area near thefanlt,or else the deformation is weak in the area far from the fault.②The intensity of crustal deformation in various fault and different period is different,which is related to the change of tectonic stress field and to the seismic activity as well.The active period of reverse successional tectonic movement of vertical fault deformation is much shorter than that of the successional one.The time, in which the turn of crustal tectonic movement occurs, is not quite identical in different regions and there is difference in time and space even for precursor anomalies of fault deformation.③ Multi-site and large scale faulting anomaly may echo each other with the strong seismic activity.
引文
1 GongShouwen.EvolutionalcharacteristicsofverticalcrustaldeformationinconjonningzonesofmassesandmassivemovementinShanGanNingQingarea[J].ActaGeophysi caSinica.1995,38(3):329-338.(inChinese)
2 JiangZaisen,ZhangXi,CuiDuxin,etal.RecenthorizontalmovementanddeformationinthenortheasternmarginofQinghaiTibetblock[J].ChineseJournalofGeophysics,2001,44(5):636-644.(inChinese)
3 ShaoHuicheng,SuGang,ZhangChunsheng,etal.AnalysisoncharacteristicsandriskofearthquakeactivityinGuanzhongregion[J].Inlandearthquake,2001,15(3):218-223.(inChinese)
2 JiangZaisen,ZhangXi,CuiDuxin,etal.RecenthorizontalmovementanddeformationinthenortheasternmarginofQinghaiTibetblock[J].ChineseJournalofGeophysics,2001,44(5):636-644.(inChinese)
3 ShaoHuicheng,SuGang,ZhangChunsheng,etal.AnalysisoncharacteristicsandriskofearthquakeactivityinGuanzhongregion[J].Inlandearthquake,2001,15(3):218-223.(inChinese)
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