Volume changes of Jacobshavn Isbrae between 1985, 1997 and 2007 ...

• Main Authors: Motyka, Roman J, Fahnestock, Mark, Truffer, Martin
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2010
• Subjects: International Polar Year 2007-2008 IPY; Airborne Topographic Mapper; glacier; Greenland; International Polar Year; IPY; Jakobshavn
• Online Access: https://dx.doi.org/10.1594/pangaea.817212; https://doi.pangaea.de/10.1594/PANGAEA.817212

Following three decades of relative stability, Jakobshavn Isbrae, West Greenland, underwent dramatic thinning, retreat and speed-up starting in 1998. To assess the amount of ice loss, we analyzed 1985 aerial photos and derived a 40 m grid digital elevation model (DEM). We also obtained a 2007 40 m grid SPOT DEM covering the same region. Comparison of the two DEMs over an area of ~4000 km**2 revealed a total ice loss of 160 ± 4 km**3, with 107 ± 0.2 km**3 in grounded regions (0.27 mm eustatic sea-level rise) and 53 ± 4 km**3 from the disintegration of the floating tongue. Comparison of the DEMs with 1997 NASA Airborne Topographic Mapper data indicates that this ice loss essentially occurred after 1997, with +0.7 ± 5.6 km**3 between 1985 and 1997 and -160 ± 7 km**3 between 1997 and 2007. The latter is equivalent to an average specific mass balance of -3.7 ± 0.2 m/a over the study area. Previously reported thickening of the main glacier during the early 1990s was accompanied by similar-magnitude thinning ... : Data extracted in the frame of a joint ICSTI/PANGAEA IPY effort, see http://doi.pangaea.de/10.1594/PANGAEA.150150 ...