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与发生在西藏北部昆仑断层西部一段的2001年M_w7.8级中昆仑地震有关的的野外地质调查使得我们可以约束约400km长、走滑位移达16.3m的同震地表破裂带。根据对野外调查得到的地质构造、构造地形特征、位移空间分布以及远震波形分析,破裂带可以分为4段。地表破裂的变形特征及震源机制解表明,该地震是一个几乎纯走滑机制的破裂。地震数据反演结果表明,破裂以双侧破裂形式起始于西端的震中区附近,并且很快以单侧破裂形式传播380km,最大破裂区局限在震中以东150～280km的子断层段上,这与野外调查结果一致。最大位移地区的平均应力降估计为7MPa,为板内地震的典型值。
The field geologic investigation related to the M_7.7 magnitude Kunlun earthquake in 2001 in the western part of the Kunlun fault in the northern part of Tibet allowed us to constrain the coseismic surface rupture zone with a length of about 400 km and a strike-slip displacement of 16.3 m. According to the geological structure, the topographic features, the spatial distribution of displacement and the analysis of teleseismic waveform obtained from the field survey, the rupture zone can be divided into four sections. The deformation characteristics of the surface rupture and focal mechanism solutions show that the earthquake is a rupture of almost pure strike-slip mechanism. The results of seismic data inversion show that the rupture started in the vicinity of the epicenter at the western end with bilateral rupture and quickly propagated 380 km in the form of unilateral rupture. The maximum rupture zone was confined to the sub-fault zone of 150-280 km east of the epicenter, This is consistent with the field survey. The average stress drop in the area of maximum displacement is estimated to be 7 MPa, a typical value for on-board earthquakes.