GPS-derived horizontal ice flow velocities along the traverse route from Zhongshan Station to Dome-A, East Antarctica

摘要

The traverse route from Zhongshan Station to Dome-A is one of the most important expedition routes of ITASE Project. China carried out 3 inland traverses during the 1996/1997, 1997/1998, 1998/1999 austral summer field seasons. The field team reached inland 300 km, 500 km and 1100 km away from Zhongshan Station respectively. Some ice motion stakes were set up, occupied and reoccupied along the route by GPS technology. It showed that the ice along the traverse route flowed with an 8-25 ma~(-1) velocity to the northwest, the direction of the bottom of Lambert Glacier Basin. They coincide with the results along the eastern section from LGB59-70 of the LGB route deduced by Australia in both values and directions. Furthermore, the directions of the horizontal flow are perpendicular to the surface topography contour. The much larger velocity at the point of LT980 with an approximate value of 100 ma~(-1) was probed. It was caused by a 15 km wide trough on the bed beneath this point.