岷县漳县6.6级地震发震构造与区域地形地貌特征关系讨论

Discussion on the Relationship between Regional Landform and Seismogenic Structure of the Minxian-Zhangxian M_s6.6 Earthquake

为了清晰认识岷县漳县6.6级地震的发震构造环境和区域地貌特征,本文利用DEM(数字高程模型)数据分析了甘东南地区的地形地貌基本特征,结合区域活动断裂分布及其运动学特征讨论了岷县漳县6.6级地震所处在的青藏高原东北缘的区域构造环境和地壳运动学特征,研究了甘肃东南部的基本构造环境、发震断裂的断裂活动性及孕震过程等基本发震条件。主要利用地形剖面方法分析了通过地震震源区的地貌特征,反映出区域地形地貌特征与发震构造的关系,从地貌学角度探讨了区域中上地壳变形特征及孕震过程。最后讨论了区域发震构造、地球动力学背景,通过地形剖面及区域地貌分析了岷县漳县6.6级地震发震构造特点,认为此次地震可能与汶川地震的同震及震后变形过程相关。

To clearly recognize and understand the geomorphologic characteristics and seismogenic structure of the Minxian-Zhangxian MS6.6 earthquake,we use DEM （Digital Elevation Model） data to analyze the landform characteristics of southeastern Gausu.Regional tectonic environment and crustal kinematic characteristics at northeastern margin of Tibet Plateau are discussed combined with the distribution of regional active faults and their kinematic features around the hypocentral region of Minxian-Zhangxian MS6.6 earthquake.The seismogenic conditions including tectonic environment,activity of seismogenic fault and seismogenic process are also studied.In this paper,we use terrain profile method to analyze the geomorphologic characteristics of source region of this earthquake to reflect the relation between regional geomorphologic characteristic and seismogenic structure.Deformation characteristic of regional middle and upper crust and seismogenic process are explored from the geomorphologic point of view.At last,regional seismogenic structure and geodynamics background are discussed.We suggest that the Minxian-Zhangxian MS6.6 Earthquake is related with coseismic and postseismic deformation process of the Wenchuan MSS.0 earthquake.