姑咱台压应变异常信号与汶川和芦山等地震的关系研究

Study of the Relationship between Compressive Strain Abnormal Signals and Wenchuan and Lushan Earthquakes at Guzá Station

对2007~2014年姑咱台应变仪第一分量的分钟值原始观测曲线进行研究。结果表明,其日、月异常合计幅值、频次和时间均在汶川地震前显著增加,日、月累加值曲线相应快速上升,2008年以后速率明显放缓,前后相差最大可达10倍、9倍和4倍,与汶川地震表现出较强的对应关系。但之后发生芦山和康定地震时,这一过程并未重现。根据龙门山一带地应力实地测量结果和视应力分析结果,对该现象进行一定程度的解释。

In this paper, we study the original observation curve of the minute value of the first component of the 2007-2014 strainmeter at Guzá station. The statistical results show that the daily and monthly anomalous total amplitude, frequency and time are significantly increased before the Wenchuan earthquake. The daily and monthly cumulative value curves increase rapidly, and the rate slows down after 2008. The maximum phase difference is 10, 9 and 4 times. So, it has a strong corresponding relationship with the Wenchuan earthquake. However, the process of the subsequent earthquakes in Lushan and Kangding does not reappear. According to the results of in-situ stress measurement and visual stress analysis in the Longmenshan area, this phenomenon has been explained to a certain extent.