2013年芦山7.0级地震的同震及震后形变模拟  

Simulation of coseismic and postseismic deformation for 2013 Lushan M7.0 earthquake

作　　者：刘冠中[1] 刘远征[2] 杜雪松[3] 苏琴[4] 

机构地区：[1]中国地震局地壳应力研究所,北京100085 [2]华北水利水电大学资源与环境学院,河南郑州450008 [3]中国地震局第一监测中心,天津300180 [4]四川省地震局测绘工程院,雅安625000

出　　处：《辽宁工程技术大学学报（自然科学版）》2014年第10期1331-1337,共7页Journal of Liaoning Technical University (Natural Science)

基　　金：国家自然科学基金资助项目(41204005);四川地壳形变跟踪研究(2014010205)共同资助

摘　　要：芦山地震发生时,龙门山断裂带的大部分跨断层短水准观测场地未记录到同震变化,为了研究芦山地震对这些场地的影响,同时也为了更准确地评估龙门山断裂带西南段的地震危险性,基于弹性位错理论和粘弹性分层岩石圈模型,模拟计算芦山地震的同震、震后形变,以及龙门山断裂带上短水准场地的同震和震后变化.结果表明:(1)芦山地震断层北西盘(上盘)同震最大水平位移约19.18 cm,整体为E和SEE向运动,南东盘(下盘)约7.55 cm,主要为NWW向运动;垂直位移场在上盘的上升比较显著,最大抬升幅度30.74 cm;(2)未来10年,由粘弹松弛引起的震后形变与同震形变相差不多,将释放与主震相当的能量,但由于龙门山断裂带西南段的滑动亏空区仍有大部分的能量未释放完全,强震危险性仍较高;(3)整体上芦山地震引起的龙门山断裂带垂向同震形变比较微弱,除宝兴场地外,其他场地的同震形变本身就很小,变化幅度小于观测精度,这可能与芦山地震发震断层为尚未出露地表的盲逆断层有关.When the Lushan M7.0 earthquake occurred on 20 Apr. 2013, most of short-leveling sites did not record the coseismic variations. In this paper, for seeking its reason, and assessing the seismic hazard more accurately, using elastic dislocation theory and viscoelastic layered half-space model, this study calculated the coseismic and postseismic deformation for the Lushan earthquake, and simulated the coseismic and postseismic variation on short-leveling sites along Longmenshan Fault Zone. The results show that： （1） The maximum horizontal coseismic displacement of the Lushan earthquake is about 19.18cm on hanging-wall, and it＇s about 7.55cm on foot-wall. The northwest side of fault moves toward E or SEE direction, while the southeast side moves toward NWW direction in general. Meanwhile, the vertical coseismic displacement is more remarkable on the hanging-wall, and the maximum value is 30.74cm. （2） The postseismic deformation in the future 10 years is comparable to the coseismic deformation, and release the equivalent energy to the main shock. So, most of energy of the slip deficit area is not released yet on southwest segment of Longmenshan Fault Zone, and it is relative dangerous as before. （3） The effects of the Lushan earthquake on Longmenshan Fault Zone are not outstanding. Except the Baoxing site, the coseismic variation itself is tiny and less than the observation accuracy and it maybe results from the blind reverse fault structure of the seismogenic fault.

关 键 词：芦山地震 同震 震后形变 短水准 地震危险性 

分 类 号：P65[天文地球—地质学]