Medium-term,Short-term and Impending-earthquake Anomaly Characteristics and Prediction of the M≥5 Grouping Earthquakes in Southwest Yunnan during May-June 2007

In May-June 2007, a group of M≥5 earthquakes occurred clusteringly in Southwest Yunnan. We gave the process of predicting the clustering activity and the dynamic evolution patterns of seismological and precursory anomalies. The Medium-term anomalies of this group earthquakes were mainly characterized by the M≥6 earthquake quiescence beyond 3 years in Yunnan and near 12 years in Southwest Yunnan, and the relatively high stress level in Southwest Yunnan since 2006 reflected by small-shock modulating ratio, high water level and the trend anomalies of some precursors. In the medium-short term stage, M≥3 earthquake increased in Southwest Yunnan and formed seismic gap. After small units ruptured, the energy centralized to a larger block, finally the large earthquake happened. In short-impending stage, small earthquakes continually moved to the epicenters and the seismic gap disappeared. In the process of moderate earthquakes clustering, M≥3 earthquake swarms happened in Southwest Yunnan and new precursor anomaly appeared before each M≥5 earthquake.