2013年云南香格里拉、德钦-四川得荣交界5.9级地震灾害及发震构造

The Seismo-Geological Hazards and Seismogenic Structure of the 2013 Deqing-Derong 5.9 Earthquake

2013年8月28日、31日,云南迪庆藏族自治州香格里拉县、德钦县、四川省甘孜藏族自治州得荣县交界地区连续发生5.1级、5.9级地震.为了查明此次地震的影响破坏程度,进行了地震现场建筑物震害考察并对震中附近断裂进行了野外构造地质剖面调查.两次地震在短时间内并在相近位置连续发生,造成了此次云南香格里拉、德钦-四川得荣交界地震比以往同级地震的破坏程度要高,地震烈度最高为Ⅷ级,有感范围大,5.9级地震宏观震中大致处在整个灾区破坏最严重的奔子栏镇争古村一带(28.20°N,99.36°E),距离地震微观震中约5.1km.等震线沿德钦-中甸断裂呈北西向分布,近似为椭球状,结合此次地震震中附近区域现场断裂调查、震源机制解数据以及地震余震空间分布特征,初步推断此次地震的发震构造为德钦-中甸断层,其主要表现为一次以正断为主兼有左旋走滑错动的地震事件.

On August 28st and 31st, 2013, two earthquakes with magnitude of 5.1 and 5.9 occurred on the boundary between Deqing County, Yunnan Province, and Derong County, Sichuan Province. In order to evaluate the damage of the earthquake, we investigated on lots of seismo-geological hazards induced by the earthquakes and conducted the field investigation of geolog- ical structural section about the fractures near the epicenter. Those two earthquakes successively occurring at the adjacent posi- tion led to the intensity of this earthquake higher than that of the same magnitude. The maximum intensity of the 5.9 earth- quake is Ⅷ degree and the perceptible area is relatively large. The macroseismie epicenter is about 5.1 km from the 5.1 micro- seismic epicenter is roughly located at the middle of the two microseismie epicenter （28.20°N, 99.36°E）. The isoseismic line is shaped as an anomalous ellipse and the orientation of its long axis is NW-SE orientation along the Deqin-Zhongdian fault. Ac- cording to the field investigation of geological structural section about the fractures near the epicenter, the focal mechanism solution data and the special distribution characteristics of the aftershocks, we preliminary infer that the scismogenic structure is Deqin Zhongdian fault and the Deqing Derong 5.9 earthquake is a normal fault type earthquake charac（erized by strike-slip.