Abstract

We document changes for Mittivakkat Gletscher, the peripheral glacier in Greenland with the longest field-based observed mass-balance and surface velocity time series. Between 1986 and 2011, this glacier changed by -15 in mean ice thickness and -30 in volume. We attribute these changes to summer warming and lower winter snow accumulation. Vertical strain compensated for �60 of the elevation change due to surface mass balance (SMB) in the lower part, and �25 in the upper part. The annual mean ice surface velocity changed by -30, which can be fully explained by the dynamic effect of ice thinning, within uncertainty. Mittivakkat Gletscher summer surface velocities were on average 50-60 above winter background values, and up to 160 higher during peak velocity events. Peak velocity events were accompanied by uplift of a few centimeters.