汶川MS8.0地震前云南地区显著前兆观测异常分析

汶川M_S8.0地震前云南地区出现了显著的前兆观测异常. 该文从大地震的孕育范围出发分析认为这些地震前兆异常可能与汶川M_S8.0地震有关， 并认识到前兆观测出现的显著极值异常可能是M_S≥7.0大地震的前兆； 有学者认为大震震源区没有或较少出现前兆观测趋势异常是大地震的共性特征， 汶川M_S8.0地震的前兆观测异常也是相同的； 地震前兆观测异常开始和结束时间是多样的， 前兆异常的分布是复杂的， 因此利用震后总结的共性特征， 在震前对汶川M_S8.0地震作出预测是困难的. 

Analysis on remarkable precursory anormalies observed in Yunnan area before Wenchuan Ms8.0 earthquake

Some remarkable anormalies of precursory observation appeared in Yunnan area before Wenchuan earthquake. According to the seismogenic scale, we think these anormalies may have a close relationship with Wenchuan M_S8.0 and realized that remarkable extremum anormalies maybe the precursor of big earthquakes with M_S≥7.0. Some researcher think it is a common character that no or few precursory anormalies appeared in epicentral area, so did the Wenchuan M_S8.0 earthquake. The beginning and ending time of anormalies were various, and the distribution of anormalies was complex. So it was difficult to predict the Wenchuan M_S8.0 earthquake using the common characters summarized after the earthquake.