INTERPRETATION OF ELEVATION CHANGES ON SVALBARD GLACIERS AND ICE CAPS FROM AIRBORNE LIDAR DATA

• Main Authors: Jonathan Bamber, William Krabill, Vivienne Raper, Julian Dowdeswell
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Svalbard; Svalbard Archipelago; Nordaustlandet; Vestfonna; Fridtjovbreen; Vegafonna; Airborne Topographic Mapper; glacier; Spitsbergen
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.496.7064; http://www.uio.no/studier/emner/matnat/geofag/GEO4420/h06/undervisningsmateriale/papers/bamber_geilo.pdf

Abstract. Precise airborne laser surveys were conducted during the spring of 1996 and 2002 using NASA's Airborne Topographic Mapper (ATM) on seventeen ice caps and glaciers in the Svalbard archipelago covering the islands of Spitsbergen and Nordaustlandet. Here, we present results of the elevation changes observed. Lower elevation, southerly located glaciers show the largest thinning rates of ~50 cm/yr while some of the higher, more northerly ice caps appear to be close to balance. The trends, however, are not unambiguous, due to a variety of factors including glacier aspect, microclimatological influences and the high natural annual variability in local accumulation and ablation rates. Anomalous results were obtained for Fridtjovbreen, which started surging in 1996, at the start of the measurement period. On this glacier, thinning (of more than 60 cm/yr) was observed in the accumulation area, coincident with thickening at lower elevations. Asymmetric thinning was found on two ice caps on Nordaustlandet with the largest values on the eastern side of Vestfonna but the western slopes of Vegafonna. The mean elevation change for all ice masses was –0.19 m a-1 water equivalent, which is 1.6 times the 30 year estimate. The increase is linked to warmer air temperatures in the late 1990s. Multiple linear regression suggests that mass balance is most closely correlated with latitude, rather than longitude or average altitude.