The 2010 Eyjafjallajökull eruption in Iceland provided a unique opportunity to quantify the evolution of proglacial geomorphology during a series of volcanogenic jökulhlaups (glacial outburst floods) (>140 events). Time-lapse imagery and repeat terrestrial laser scans before and directly after the eruption show that the jökulhlaup of 14 April 2010 composed 61% of the 57 × 10 6 m 3 total discharge of the combined events, and had the highest peak discharge for the two main ﬂ ood events, but only deposited 18% of the total volume of sediment in front of Gígjökull glacier. The majority of sediments (67% of a total volume of 17.12 × 10 6 m 3 ) were deposited by the 15 April 2010 jökulhlaup, and this was followed by extensive reworking by a series of smaller jökulhlaups over the following 29 days that deposited 15% of the total sediment. The geomorphological and sedimentary signatures of the two largest jökulhlaups associated with the onset of the eruption have either been reworked by later ﬂ oods or are buried by later ﬂood deposits. Consequently, the ice-proximal, post-eruption landscape cannot be used to reconstruct the characteristics or magnitudes of either of the two largest jökulhlaups. The ﬁ ndings support a complex-response model in which peak discharge and the bulk of the sediment transported is decoupled by changing routing mechanisms and water:sediment ratios during the eruption.