Data di Pubblicazione:
2006
Citazione:
Rates, processes and morphology of freshwater calving at Miage Lake (Italian Alps) / G. Diolaiuti, M. Citterio, T. Carnielli, C. D'Agata, M. Kirkbride, C. Smiraglia. - In: HYDROLOGICAL PROCESSES. - ISSN 0885-6087. - 20:10(2006), pp. 2233-2244.
Abstract:
The rates and processes of freshwater calving at Miage Glacier (Mont Blanc Massif, Italy) are described. Calving at
Miage Glacier has occurred for two centuries on its right-lateral side, into a small ice-marginal lake (Miage Lake).
Field surveys identified the main processes leading to iceberg production and quantified the calving losses over a
summer season. Calving losses were compared (1) with the surface ablation of the debris-covered tongue, evaluated
through a simple model based on measured ablation rates at different altitudes and debris cover thicknesses, and
(2) with other inputs to the lake (stream inflow discharge) and with the lake volume. Results show that thermal
undercutting by warmer surface water plays an important role in driving ice-cliff evolution. Thermal notches grow
at ¾30–35m year1 and cause a similar amount of cliff retreat. Calving contributes ¾2% of the estimated summer
runoff from the debris-covered part of the ablation zone, but this is equivalent to ¾38% of the lake volume, and is of
the same magnitude as the mean discharge from the inflow streams. These data indicate that calving of the ice cliff is
one of the main water sources for maintaining the lake at the maximum summer volume, with the surface at the level
of the subaerial outlet stream. A survey of Italian calving glaciers shows that calving is becoming more widespread,
and that debris covers are present at all calving ice margins. The lake–ice interactions described in this study can,
therefore, be considered to have wider representativeness.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Italian Alps ; Miage Lake ; freshwater calving ; ice cliff ; DEM ; debris-covered glacier ; ablation rate ; runoff
Elenco autori:
G. Diolaiuti, M. Citterio, T. Carnielli, C. D'Agata, M. Kirkbride, C. Smiraglia
Link alla scheda completa: