Geodetic Positions of Borehole Sites of the Greenland Ice Sheet Program.

摘要

Eight Geoceiver stations were established and suitably marked along or near the crestiline of the Greenland ice sheet during GISP field operations from 1971 to 1975. At one of these stations, DYE-3, repeated Geoceiver positions indicate an ice velocity of 12.7 m.yr on an azimuth of approximately 60 degrees. Data from the International Greenland Glaciological Expedition (EGIG) surveys show that ice flow in the vicinity of Crete is radiating outward from a dome to the south. Two independent calculations of the state of equilibrium at Crete indicate ice sheet thinning rates of 0.25 to 0.37 m/yr, while direct measurement of elevation change by EGIG indicates an ice sheet thickening rate of difference of 0.06 m/yr. Resolution of these differences must await further geophysical work and deep drilling in the ice sheet. (Author)