根据GPS和水准资料反演2008年汶川地震同震破裂模型
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摘要
通过分析2008年汶川8.0级地震前后的GPS观测资料和1983~2010年的精密水准观测资料,得到地表同震位移场。结合野外地质调查,反演了汶川地震同震断层几何模型和断层面上滑动分布。反演结果表明:北川—映秀断裂是一个铲形断层,长度为180km,地表倾角为62°,随指数函数形式逐渐变缓,深度18km,断层面滑动以逆冲为主;青川断裂长为120km,倾角为58°,断层面上走滑分量由南向北逐渐增加;灌县—江油断裂为纯逆冲断层,长度为80km,倾角35°。整个断层模型中最大错动量达到7.6m,对应破坏最严重的北川地区。本次地震释放的地震矩为7.62×1020N·m,相应矩震级为MW7.9。反演所得模型对于近场的水准观测资料和GPS观测资料拟合很好。
Basing on the GPS and precise leveling observation data before and after Wenchuan M8.0 earthquake in 2008,we got its co-seismic displacements fields.Combining the field geological investigation,we inversed the geometric model of co-seismic fault and slip distribution on the fault plane.The inversion results show that Beichuan-Yingxiu fault is a listric fault with a length of 180 km,the dip on the ground is 62° and decreases gradually in exponential function along with the depth increase.The depth of the fault is 18 km and the slip on the fault plane is mainly the thrust motion.The length and dip of Qingchuan fault is 120 km and 58° respectively,and the strike-slip component increases gradually along the strike from south to north.The Guanxian-Jiangyou fault is a thrust fault with the length of 80km and the dip of 35°.The maximum slip of the fault model is 7.6 m,which is corresponding to Beichuan area in most severe damage.The seismic moment releasing of Wenchuan M8.0 earthquake is estimated to be 7.62×1020 N·m,and its corresponding moment magnitude is MW7.9.The geometric model of co-seismic fault is well fit for GPS and precise leveling observation data.
引文
①http://earthquake.usga.gov/eqcenter/eqinthenews/2008/us2008ryan.
    ②http://www.globalcmt.org/CMTsearch.html.
    陈运泰,许力生,张勇,等.2008.2008年5月12日汶川特大地震震源特性分析报告[R].http://www.csi.ac.cn/sichuan/chenyun-tai.pdf.
    国家重大科学工程“中国地壳运动观测网络项目组”.2008.GPS测定的2008年汶川MS8.0级地震的同震位移场[J].中国科学(D辑:地球科学),38(10):1195-1206.
    黄媛,吴建平,张天中,等.2008.汶川8.0级大地震及其余震序列重定位研究[J].中国科学(D辑:地球科学),38(10):1242-1249.
    万永革,沈正康,王敏,等.2008.根据GPS和INSAR数据反演2001年昆仑山口西地震同震破裂分布[J].地球物理学报,51(4):1074-1084.
    王敏.2009.基于GPS同震位移场约束反演2008年5·12汶川大地震破裂空间分布[J].地球物理学报,52(10):2519-2526.
    王卫民,赵连锋,李娟,等.2008.四川汶川8.0级地震震源过程[J].地球物理学报,51(5):1403-1410.
    王阎昭,王恩宁,沈正康,等.2008.基于GPS资料约束反演川滇地区主要断裂现今活动速率[J].中国科学(D辑:地球科学),38(5):582-597.
    徐锡伟,闻学泽,叶建青,等.2008.汶川MS8.0地震地表破裂带及其发震构造[J].地震地质,30(3):597-629.
    许才军,刘洋,温扬茂.2009.利用GPS资料反演汶川MW7.9地震滑动分布[J].测绘学报,38(3):195-201.
    张希,崔笃信,蒋锋云.2009.基于GPS观测的汶川地震参数反演与库仑应力变化分析[J].地震研究,32(4):351-356.
    Okada Y.1985.Surface deformation due to shear and tensile faults in ahalf space[J].BSSA,75(4):1135-1154.
    Shen Z K,Jackson D D,Feng Y J,et al.1994.Postseismic deformationfollowing the Landers earthquake California,28June1992[J].BSSA,84(3):780-791.
    Shen Z K,Sun J B,Zhang P Z,et al.2009.Slip maxima at fault junctions and rupturing of barriers during the 2008 Wenchuan earthquake[J].Nature Geoscience,2:718-724.
    Shen Z K,Jackson D.1993.GPS reoccupation of early triangulation sites:tectonic deformation of the Southern Coast Ranges[J].J G R,98(B6):9931-9946.
    Wang Q L,Cui D X,Zhang X,et al.2009.Coseismic vertical deformationof the MS8.0Wenchuan earthquake from repeated levelings and its constraint on listric fault geometry[J].Earthq Sci,22(6):595~602.
    Wang Q,Qiao X,Lan Q,et al.2011.Ruputre of deep faults in the 2008 Wenchuan earthquake and uplift of the Longmen Shan[J].Nature Geoscience,(4):634-640.

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