Investigation of the Macroscopic Anomalies before and after the M8. 0 Wenchuan Earthquake

The macroscopic anomalies before and after the May 12,2008 Wenchuan M8. 0 earthquake were collected and analyzed in this paper. The credible anomalies occurring from February 1 to June 10,2008 were treated as macroscopic anomalies,and their space-time distribution was studied. The research indicates that in time distribution,the number of macroscopic anomalies peaked before the earthquake,and these peak values appeared twice after the earthquake. In space distribution,the distribution of macroscopic anomalies before the earthquake was the same as that after the earthquake. In this paper,the mechanism of occurrence of macroscopic anomalies and the role of macroscopic anomalies in forecasting earthquake were also discussed.