A new regional high-resolution map of basal and surface topography for the Greenland ice-sheet margin at Paakitsoq, West Greenland

In 2005 an airborne survey was carried out from a Twin Otter aircraft at Pâkitsup Akuliarusersua (Paakitsoq) near llulissat in West Greenland. The survey aimed to measure ice thickness with a 60MHz coherent radar and surface elevation with a scanning laser altimeter. Positioning information came from multiple on-board differential GPS units and an inertia! navigation system. The region surveyed covers >80km along the ice margin and has a total area of ∼2700km2 with varying density of measurements: the between-track distance was ∼1 km near the margin, increasing to ~3 km away from the margin. Regional high-resolution maps of basal topography under the Greenland ice sheet are useful for resolving important glaciological and hydrological questions and for enhancing related process studies, such as the influence of basal meltwater on ice dynamics. The ice-sheet margin in this region is also currentiy under consideration for hydropower development and has a long and continuing history of glaciological investigations, lately with emphasis on the connection between surface meltwater formation and surface velocity of the ice sheet. Here we present a new regional map of the surface and basal topography of the ice-sheet margin and discuss some of the implications for reported observations at Swiss Camp.