摘要：We have constructed a new digital elevation model (DEM) of the 1995 surface of Black Rapids Glacier, a surge-type glacier in the central Alaska Range, using ERS-1/-2 repeat-pass interferometry. We isolated the topographic phase from three interferograms with contrasting perpendicular baselines. Numerous phase-unwrapping errors caused by areas of poor coherence were corrected in all three interferograms, using a novel, iterative, semi-automated approach that capitalizes on the multi-baseline nature of the dataset. Comparison of our DEM with a 1949 US Geological Survey DEM and with 1973–95 ground survey data shows the gradual return of Black Rapids Glacier to a pre-surge hypsometry following a surge in 1936/37. Maximum elevation changes along the glacier center line in the ablation and accumulation areas are, respectively, −249 and 63 m (−5.4 and 1.4 m a −1 ). Maximum elevation changes of survey points at nearby locations are −4.9 m a −1 (1975–84) and 0.5 m a −1 (1975–85). Center-line thickening of 62 m between 1949 and 1995 ( 1.4 m a −1 ), just above the Loket tributary in the upper part of the ablation zone, indicates dynamic thickening following the 1936/37 surge.
