Substantial thinning of a major east Greenland outlet glacier

Aircraft laser-altimeter surveys in 1993 and 1998 over Kangerdlugssuaq Glac ier in east Greenland reveal thinning, over the 5-year interim, of several meters for all surveyed areas within 70 km of the seaward ice front, rising to 50 meters in the final 5 km. Such rapid thinning is best explained by i ncreased discharge velocities and associated creep thinning, most probably caused by enhanced lubrication of the glacier bed. The calving ice front ov er the past decade has occupied approximately the same location as in 1966. Velocity estimates for 1995/96 are about the same as those for 1966 and 19 88, but significantly less than for 1999, suggesting that major thinning be gan after 1995.