关键词: 康定地温, 小震活动, 芦山地震, 地应力

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