jgg     2009 29 (3):  16-23    ISSN: 0412-1961  CN: 21-1139/TG P315.73P315.73NEGATIVE DISLOCATION MODEL OF VERTICAL CRUSTAL MOVEMENT AND BACKGROUND BEFORE WENCHUAN AND PANZHIHUA EARTHQUAKES Zhang Xi 1,2) ; Zhang Sixin 2) ; and Wang Shuangxu 2) 1)Institute of Earthquake Prediction, CEA, Beijing 1000362)Second Monitoring and Application Center, CEA, Xi’an 710054 Received: 1900-01-01  Revised: 1900-01-01  Online: null Supporting info null