Crustal Movement Observed by GPS and Earthquake Activity in the Chinese Mainland and its Neighborhood

The general characteristics of the recent horizontal crustal movement in the Chinese Mainland and the horizontal crustal movements before the Kunlun Mountain earthquake of M8.1 on Nov. 14, 2001 and two earthquakes of M 8.0 and M 7.9 occurred in Sept. 2003 around the Chinese Mainland are analyzed with GPS data obtained in the Crustal Movement Observation Network of China (CMONOC). Relative vertical displacements observed in the last five years at fiducial stations show that there was a significant correlation between the length of day and the vertical displacements at most stations in western China.