2003年大姚和民乐—山丹地震1年尺度预测

One-Year Prediction for the Dayao and Minle-Shandan Earthquakes in 2003

介绍了2003年云南大姚MS6.2,6.1和甘肃民乐—山丹MS6.1,5.8地震三要素的1年尺度预测情况,讨论了震中附近的地电阻率中短期异常特征。应用岩石加载实验中电阻率变化和DD模式解释了民乐—山丹地震前山丹地电的异常变化过程;大姚地震前同一活动断裂带上相邻台站其异常的相似性、同步性与以往的震例研究吻合;两组地震前电阻率中短期异常的各向异性变化与震源机制解的最大主压应力方位的关系明显,可以判定,这两组强地震附近地区的地电阻率异常与强地震的晚期孕育过程有关。

We introduced the procession that the three elements of the Dayao, Yunnan, M_S6.2, 6.1 earthquakes and the Minle-Shandan, Gansu, M_S6.1, 5.8 earthquakes in 2003 were made one-year predictions, and discussed the medium-, short-term anomalies of earth resistivity near the foci. It is thought that using the loading experiment result of rock and the DD model can explain the change processes of the resistivity anomalies observed at Shandan station before the Minle-Shandan earthquakes; the similarity and synchronism of the anomalies that were observed at two adjacent stations along the same active fracture zone before the Dayao earthquakes are coincident with the previous earthquake example research results; the anisotropic changes of the medium-, short-term anomalies are obviously related to the maximal principal compressive stress orientations of the focal mechanism solutions before two groups of earthquakes, and we can theoretically explain the anisotropic changes. Therefore, we believe that the earth resistivity anomalies appared in the areas near the two groups of strong earthquakes are related to the later preparation processes of the earthquakes.