Quantification and analysis of dynamic mass loss from Greenland’s peripheral glaciers

Abstract:

While global glacier mass balance has decreased rapidly over the last two decades, mass loss has been greatest in regions with marine-terminating glaciers. In Greenland, peripheral glaciers and ice caps (GICs) cover only ~5% of Greenland’s area but contributed ~14-20% of the island’s ice mass loss between 2003-2008. Although GIC’s contribution of surface meltwater runoff to regional ice mass loss has been estimated using atmospheric models, mass loss due to changes in glacier terminus position and accelerated ice flow remains unquantified. Here, I estimate annual ice discharge from 641 marine-terminating glaciers using time series of ice velocity and ice surface elevation, also accounting for changes in terminus position over time. The results confirm that, similar to the ice sheet’s outlet glaciers, Greenland’s GICs have largely retreated and dynamically accelerated since the start of the 21^st century. We do, however, find interesting spatial and temporal patterns in glacier dynamics around Greenland’s periphery which we attribute to regional variations in glacier geometry and climate.