South American SLR stations monitoring ground displacement caused by the M8.8 Chilean earthquake of 2010

The M8.8 Chilean earthquake of February 27,2010 caused a large surface displacement near its epicenter.Satellite Laser Ranging(SLR) station 7405,cooperatively operated by Germany and Chile about 130 km from the epicenter was affected by the earthquake.Another SLR station,No.7406,operated jointly by the National Astronomical Observatories of the Chinese Academy of Sciences and San Juan University of Argentina,was about 600 km from the epicenter.Combining the observations of these two SLR stations with global SLR station observations,we calculate the geocentric coordinates of the two stations based on ITRF2000.The results show that the coordinates of the two stations have changed by varying degrees.SLR-7405 moved substantially towards the southwest with displacements of about 3.11,0.52 and 0.49 m in X,Y,Z directions;the corresponding displacements for SLR-7406 are about 0.02,0.03 and 0.02 m.This solution,as an independent result derived from SLR observations,could provide an essential external check for other positioning techniques such as GPS.