Abstract:

Recently,the strong earthquakes in China mainland occurred mainly around the Bayanhar block. It is important to monitor the information of ongoing crustal activity at the key tectonic positions. We have developed a set of wireless equipment for measuring the ground temperature in field,and have established a network of measurement of the ground temperature along Xianshuihe Fault. Some changes of temperature were observed before and after the Lushan earthquake on April 20,2013.First of all,an apparent and persistent change of the ground temperature in Kangding appeared,starting from January 31,2013.This temperature variation corresponded with the occurrence of the small earthquakes around the observation station. According to the relationship between the temperature and stress,the abrupt change of ground temperature is essentially the geological stress adjustment. From the viewpoint of geological structures,both Longmengshan Fault and Xianshuihe Fault are the boundary faults of the Bayanhar block,but located at different boundaries,so,Kangding in Xianshuihe Fault is tectonically related to Lushan in Longmengshan Fault. Thus,the temperature change described above would possibly be the precursor of the Lushuan earthquake.

Key words: ground temperature, small earthquake activity, Lushan earthquake, crustal stress

摘要：

近年来,中国大陆强震主要发生在巴颜喀拉地块周边,该地块成为近期中国大陆强震主体地区。在一些关键构造部位,开展地壳活动信息监测具有重要的实际意义。作者所在研究组专门研发了适于野外观测的无线地温遥测设备,在鲜水河断裂带建立了无线地温遥测台网。在2013年4月20日的芦山地震前后,观测到了一些值得关注的现象: 从2013年1月31日开始,康定地温出现持续变化,并与台站周围小震活动存在良好的对应关系。根据温度与力之间的关系,基岩温度突变的内在本质是应力调整。从构造角度看,龙门山断裂带和鲜水河断裂带同属于巴颜喀拉地块的不同边界,康定测点与芦山地震之间存在关联性,上述温度变化可能与芦山地震有关。

关键词: 康定地温, 小震活动, 芦山地震, 地应力