Changes in the southeast Vatnajökull ice cap, Iceland, between ~ 1890 and 2010

• Published in: The Cryosphere
• Main Authors: H. Hannesdóttir, H. Björnsson, F. Pálsson, G. Aðalgeirsdóttir, Sv. Guðmundsson
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2015
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; Vatnajökull; glacier; Ice cap; Iceland; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-9-565-2015; https://doaj.org/article/d166bf4126234a84992fdd200ffc1238

Area and volume changes and the average geodetic mass balance of the non-surging outlet glaciers of the southeast Vatnajökull ice cap, Iceland, during different time periods between ~ 1890 and 2010, are derived from a multi-temporal glacier inventory. A series of digital elevation models (DEMs) (~ 1890, 1904, 1936, 1945, 1989, 2002, 2010) are compiled from glacial geomorphological features, historical photographs, maps, aerial images, DGPS measurements and a lidar survey. Given the mapped basal topography, we estimate volume changes since the end of the Little Ice Age (LIA) ~ 1890. The variable volume loss of the outlets to similar climate forcing is related to their different hypsometry, basal topography, and the presence of proglacial lakes. In the post-LIA period, the glacierized area decreased by 164 km 2 (or from 1014 to 851 km 2 ) and the glaciers had lost 10–30 % of their ~ 1890 area by 2010 (anywhere from 3 to 36 km 2 ). The glacier surface lowered by 150–270 m near the terminus and the outlet glaciers collectively lost 60 ± 8 km 3 of ice, which is equivalent to 0.15 ± 0.02 mm of sea-level rise. The volume loss of individual glaciers was in the range of 15–50%, corresponding to a geodetic mass balance between −0.70 and −0.32 m w.e. a −1 . The annual rate of mass change during the post-LIA period was most negative in 2002–2010, on average −1.34 ± 0.12 m w.e. a −1 , which is among the most negative mass balance values recorded worldwide in the early 21st century.