Equilibrium Line Altitude reconstruction of the LGM paleoglaciers between the south-eastern Alps and the Northern Dinarides

The south-eastern European Alps are characterized by a forealpine belt facing the foreland with relieves rarely exceeding 2000 m in elevation. During the Last Glacial Maximum (LGM), this area saw the growth of isolated glaciers around the highest peaks. Because they were disconnected from the major ice-streams, which flowed down the Alpine valleys towards the foreland, their reconstruction is an important tool for establishing paleoclimate conditions using the calculation of their Equilibrium Line Altitude (ELA). Through field and remote sensing analyses we reconstructed the paleoglaciers of the Mount Raut (2025 m a.s.l.) in the Carnian Forealps, the Mount Chiampon - Cuel di Lanis (1700 m a.s.l.) in the Julian Forealps and the Trnovski Gozd (1495 m a.s.l.) in the Northern Dinarides. The Mount Raut is one of the highest mountains located close to the Friuli Piedmont plain, and its cirques hosted a glacier during the last glaciations. The frontal moraines are well preserved close to the Lake Ca' Selva at about 600 m a.s.l. According to the glacier reconstruction obtained with the tool GlaRe (Pellitero et al., 2015, 2016), the LGM ELA of the Raut paleoglacier was calculated at ~1340 m a.s.l. The Mount Chiampon - Cuel di Lanis is a 6-km long crest with several cirques in the northern side and well-preserved moraines at 600-800 m a.s.l. Five paleoglaciers were distinguished. They provide ELAs at ~1200 m a.s.l. (Monegato, 2012). The Trnovski Gozd karst plateau hosted small glaciers with an overall area of ~5 km2. Glaciers covered the karstic relief on the north-facing slopes below the highest crest and their ELA was estimated at ~1240 m a.s.l. (?ebre et al., 2014). In respect to other ELAs available in the Alps (Federici et al., 2016), these lower values may suggest a lowering of the mean annual air temperature towards the east. Low-elevated ELAs were calculated also for the Little Ice Age (LIA) glaciers of the Mount Canin (Colucci, 2016). Considering the present-day high mean annual precipitation of the Carnian and Julian sectors (about 2500 mm and 3200 mm w.e.), low values of ELAs both during the LGM and the LIA could be supported by the maintaining of these precipitation rates during the cold phases. This allowed the growth of many isolated glaciers in the forealps during the LGM and the spread of the Tagliamento glacier in the Friuli Piedmont plain despite its low-elevated accumulation area, not exceeding 2800 m in elevation. References Colucci 2016 - ESPL 41, 1227-1240 Federici et al., 2016 - GSL Sp. Publ. 433, 137-159. Monegato 2012 - AMQ 25, 5-14. Pellitero et al. 2015 - Computers & Geosciences 82, 55-62. Pellitero et al. 2016 - Computers & Geosciences 94, 77-85. ?ebre et al., 2014 - Dela 39, 157-170.