The Alps: glacial landforms during the deglaciation (18.9–14.6 ka)

The deglaciation period in the Alps was characterised by the collapse of the huge system of interconnected glaciers. Active valley glaciers almost disappeared from most of the catchments, stagnant and downwasting ice remnants filled the main valleys during the earliest part of the Alpine Lateglacial, which is defined as the phase of ice decay (19–18 ka, in some sectors until 17 ka). In the lower valley reaches of the south-eastern sector tree vegetation had already started to recover. A short readvance and glacier front stabilisation took place at 17–16 ka (Gschnitz stadial) with the formation of prominent moraines, with most of the evidence coming from the Eastern Alps. This can be related to the ‘Ragogna oscillation’ cooling recognised in the south-eastern sector, which is highlighted by a period of reduced forest cover. At the end of GS2, before the onset of the Bølling interstadial, Alpine glaciers had already withdrawn and forest environments were spreading rapidly.