青藏高原北缘地应变演化特征  

Evolution characteristics of crustal strain in the northern margin of Tibetan Plateau

作　　者：王帅[1] 张永志[1] 牛玉芬[1] 姜永涛[1] 

机构地区：[1]长安大学地质工程与测绘学院,西安710054

出　　处：《地球物理学进展》2015年第1期57-60,共4页Progress in Geophysics

基　　金：国家自然科学基金项目(41374028;40674001;41304013);国土资源大调查项目(1212010914015);中央高校基本科研业务费专项资金(CHD2012TD004);陕西省教育厅自然科学科研项目(12JK0798)联合资助

摘　　要：利用青藏高原北缘中国地壳运动观测网络1991-2013年间的GPS水平速率观测结果,对青藏高原北缘不同时期的面应变和面应变率梯度进行了计算,分析了地应变的时空演化特征,并结合不同时期发生的中强以上地震,研究了地震分布与地应变时空演化特征的关系.结果表明:2001年11月14日Ms 8.1级昆仑山口西地震发震断裂对其南部区域的面应变调整结果影响较大,阿尔金断裂滑动速率的分段差异性可能控制着阿尔金断裂及塔里木盆地区域的面应变变化.青藏高原北缘面应变率梯度时空演化特征较为明显,其高值区影响范围随时间不断变化,表现为由小-变大-变小的时空演化特征,与震后地壳松弛和区域构造变形的调整有关.北缘中南部出现面应变率梯度"盆地"区,面应变率梯度量值较低,Ms5.0级以上地震有向该"盆地"聚集的趋势,该区有可能为应变积累的高值区,发生地震的可能性较大;地震空间分布的聚集性与区域地壳运动变形空间分布的趋势性相呼应.Based on the horizontal velocity of GPS data observed in the northern margin of Tibetan Plateau from 1991 to 2013,the surface strain rates and corresponding gradient were calculated using the Least Squares Collocation（LSC）method,and the temporal-spatial evolution characteristics of crustal strain were analyzed,what＇s more,in this paper,the relationship between the spatial distribution of earthquakes and the temporal-spatial evolution characteristics mentioned above was studied combining with the recorded moderate-strong earthquakes happened in different periods within the studied area.Finally we draw the conclusions：The Kunlun earthquake（Ms 8.1） posed a positive effect on the strain adjustment results for the southern area of Kunlun earthquake seismogenic fault.The strain variation,for the area along Altyn fault and Tarim basin,may be controlled by the piecewise slip rates of Altyn fault.The strain evolution characteristics in the northern margin of Tibetan Plateau were remarkable,following the little-big-small evolution characteristics with the space-time.A strain rates gradient ＂Basin＂ with low value appeared in the middle southern of the studied area,the level above Ms 5.0earthquakes possess a tendency to this ＂Basin＂,indicated that the strain accumulation in this area is possibility high and has a great possibility of strong earthquakes in the future.

关 键 词：青藏高原北缘 面应变率梯度 阿尔金断裂 昆仑山地震 

分 类 号：P541[天文地球—构造地质学] P315[天文地球—地质学]