DEVELOPING CHARACTER OF CRUSTAL DEFORMATION IMMINENT ANOMALIES BEFORE SOME EARTHQUAKES

Seven crustal deformation anomalies before some earthquakes are analyzed in this paper.Through analysis five basic shape characters are summed up,which are: (1)suddenly change in the early stage; (2)anomalies usually recover before the occurrence of an earthquake and the quake usually does not occur during the sudden change period; (3)the quake occurrence time is usually at about one month after the anomalies recovered; (4)magnitude of the earthquake has no obvious corresponding with the extent of the anomalies quantitatively; (5)the effective radius of the anomaly is about 200 kilometers.Based on the analysis,we further discussed the physical mechanism for the shape characters of the anomalies.