The geodetic mass balance of Eyjafjallajökull ice cap for 1945–2014: processing guidelines and relation to climate

Abstract

Mass-balance measurements of Icelandic glaciers are sparse through the 20th century. However, the large archive of stereo images available allows estimates of glacier-wide mass balance in decadal time steps since 1945. Combined with climate records, they provide further insight into glacier-climate relationship. This study presents a workflow to process aerial photographs (1945-1995), spy satellite imagery (1977-1980) and modern satellite stereo images (since 2000) using photogrammetric techniques and robust statistics in a highly automated, open-source pipeline to retrieve seasonally corrected, decadal glacier-wide geodetic mass balances. In our test area, Eyjafjallajökull (S-Iceland, ~70 km2), we obtain a mass balance of <![CDATA[$, with a maximum and minimum of and , respectively, attributed to climatic forcing, and , mostly caused by the April 2010 eruption. The reference-surface mass balances correlate with summer temperature and winter precipitation, and linear regression accounts for 80% of the mass-balance variability, yielding a static sensitivity of mass balance to summer temperature and winter precipitation of-2.1 ± 0.4 m w.e.a-1K-1 and 0.5 ± 0.3 m w.e.a-1 (10%)-1, respectively. This study serves as a template that can be used to estimate the mass-balance changes and glaciers' response to climate.