Deglaciation dynamics following the Little Ice Age on Svalbard: Implications for shaping of landscapes at high latitudes

The late culmination of the Little Ice Age (LIA) on Svalbard allows a detailed reconstruction of the landscape's response to the subsequent climatic warming. The study area comprises a small glacier (400-1000 m a.s.l.), on the south side of Adventfjorden (78°11′N) that was polythermal during the LIA and turned into a passively down-wasting cold-based ice-mass prior to 1936. Reconstruction of the formation and decay of ice-cored moraines and the shifting courses of glacial meltwater shows that sediment transport during deglaciation occurred in a slow, stepwise fashion with glacial landforms and sediments being slowly replaced by fluvial morphologies and slope-waste products. The key controlling factors are melting rates, aspect and surface gradients. A low melting rate and slow reworking of glacial debris promote the formation of a lag or “pavement” on low-gradient surfaces and debrisfall deposits along steeper slopes. Both products easily may be misinterpreted as a result of weathering and non-glacial processes.