Decade-scale recovery of the Eyjafjallajökull ice cap, Iceland, after the 2010 summit eruption

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Abstract Several eruptions at glaciated volcanoes have been witnessed during the last two centuries. However, most studies have focused on understanding the volcanic products or the hazard implications. Less attention has been put into analyzing the long-term effects on the glaciers. The 2010 summit eruption of Eyjafjallajökull (Iceland) provides an excellent opportunity to study such impacts by investigating how individual areas of the ice cap have changed with time. These include (i) the summit caldera (formation of vents/lava), (ii) the southern flank (short-lived eruption fissure), and (iii) the outlet glacier Gígjökull (lava propagation). We used high-resolution satellite data acquired by Pléiades and SPOT5, complemented by airborne LiDAR, to calculate elevation and volume changes of the glacier over varying time periods between 2008 and 2024. From August 2010 to August 2014, the main vent showed an elevation increase of ~ 80 m; visible eruption impacts on the southern flank have completely vanished; Gígjökull significantly recovered. However, the ice cap overall is shrinking. The area decreased from 72.3 km 2 (2010) to 63.5 km 2 (2024), with an average elevation change of −8.3 m. The caldera and Gígjökull did not follow this trend and showed an average elevation increase of ca. 13.4 m (1.0 m/year). We hypothesize that the depressions formed by the eruption acted as traps for drifting snow in winter, resulting in a local thickening rate far exceeding the average winter accumulation. Although the recovery is exceptional, the volume still only corresponds to around 50% of the ice loss caused by the eruption.

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