Glacimarine sedimentation in Kangerdluk (Disko Fjord), West Greenland, in response to a surging glacier

Beginning in 1995, a large outlet glacier of the Sermersauq Ice Cap on Disko Island surged 10.5 km downvalley to within 10 km of the head of the fjord, Kuannersuit Sulluat, reaching its maximum extent in summer 1999 before beginning to retreat. Sediment discharge to the fjord increased from 13×103 t day−1 in 1997 to 38×103 t day−1 in 1999. CTD results, sediment traps and cores from the 2000 melt season document the impact of the surge on the glacimarine environment of the fjord. Within 4 km of the inflow sedimentation rates increased by 30 times over those before the surge, reaching an estimated maximum value of 29 cm a−1 (up to 4.2 mm day−1 between 24 July and 9 September 2000). Fine-grained deposits from suspension in the water column displayed diurnal laminations in response to the interaction of tidal cycles with the sediment plume; these are not found in the sediments deposited before surging. Thin beds of sandy turbidites from turbidity currents originating from slope failures on the delta front occurred at about 20 day intervals during the melt season. Each of these effects was limited to within several kilometres of the point of inflow, but provide a unique signal significantly different from those generated by normal hydroclimatically induced events.