Abstract:

It is urgent and necessary to study crustal motion especially in vertical direction along with high frequency happening of Earthquake and geological disasters, while the precondition is to study and establish reference datum of vertical crustal motion. Aiming at the status of disunity of global vertical crustal motion reference datum in domestic and overseas, its essentiality was analyzed to study global uniform reference datum of vertical crustal motion. The project of global vertical crust motion reference datum was put forward and established through SLR vertical velocity field in ITRF2008 frame, whose rationality was demonstrated too. The systematic bias between other velocity field and SLR vertical datum was resolved by using GPS and VLBI observations, and realized the unity of other velocity field and global vertical crustal motion reference datum. Because of abundant geophysical information, expansibility, advancing and relative to the Earth Center, it is recommended that the vertical datum achieved by SLR techniques under the ITRF2008 framework is suitable as a reference datum of the global vertical crustal motion.

Key words: Crustal motion, vertical datum, SLR (Satellite Laser Ranging), ITRF (International Terrestrial Reference Frame), systematic bias model