云南鲁甸“8·03”地震地表破裂与大型地震滑坡

Surface Ruptures and Large-scale Landslides Caused by “8·03” Ludian Earthquake in Yunnan,China

云南鲁甸"8·03"地震造成重大的人员伤亡和财产损失,诱发大量次生山地灾害。根据实地考察和遥感解译,在地震烈度Ⅸ度区内发现一条地震地表破裂带,沿破裂带发育有4个(特)大型滑坡和一个高危堰塞湖。该破裂带具有典型的右旋走滑特征,系右旋走滑断层活动的结果。根据其发育特征,该断层应为"包谷垴-小河断裂"沿小河-乐红镇方向的延伸部分,对地震灾区次生山地灾害的分布起着重要的控制作用,也是4个大型滑坡形成的重要动力来源。综合分析断层的位置特征和大型地震灾害的分布情况,推断该断层为本次地震的发震断层。建议进一步加强该发震断层诱发次生山地灾害的调查与分析,防止次生山地灾害造成新的危害。

The August 3,2014 Ludian Earthquake（ Ms 6. 5）（ ＂8 ·03＂ Ludian Earthquake）,resulted in more than 600 deaths and significant property losses,has induced thousands of secondary geo-hazards. According to field investigation and remote sensing interpretation,it was found that there was an earthquake surface rupture zone with four large-scale landslides and a high-risk quake-lake around it in the Ⅸ- degree seismic intensity area. The zone is characterized by typical right-lateral strike-slip,which means that it caused by the activity of a right-lateral strike-slip fault. Therefore,the earthquake surface rupture is an outcrop of the fault. According to the features of the outcrop,it should be an extension of Baogunao- Xiaohe Fault along the direction from Xiaohe to Lehong towns（ NW- SE）. The fault,which controlled the distribution of secondary geo-hazards induced by the earthquake,was an important factor for the formation of the four large-scale landslides. Based on analysis of the fault location features and the distribution of the four large-size landslides,it was convinced that the fault was also seismogenic fault of the earthquake and characterized by right-lateral strike-slip. It was suggested that the investigation and prediction research of secondary geo-hazards induced by the seismogenic fault should be strengthened to prevent new damages by the secondary geo-hazards.