Validation of avalanche numerical simulations using dendrochronology in the Patagonian Andes

CASTELLER, A.,; CHRISTEN, M.,; VILLALBA, R.,; MARTÍNEZ, H.,; STÖCKLI, V.,; LEIVA, J.C; BARTELT , P

Vancouver, Canada

Conferencia; Conferencia. First AmeriDendro Conference 2008. University of British Columbia 23-27 de junio 2008; 2008

University of British Columbia

Title: Validation of avalanche numerical simulations using dendrochronology in  the Patagonian Andes Authors: Alejandro Casteller (1,2), Marc Christen (2), Ricardo Villalba (1), Hugo Martínez (3), Veronika Stöckli (2), Juan Carlos Leiva (1), Perry Bartelt (2) (1) Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales IANIGLA, CCT Mendoza, CONICET, Argentina; (2) WSL, Swiss Federal Institute for Snow and Avalanche Research SLF, Switzerland; (3) IDEPRN, Facultad de Ingeniería UNCuyo, CONICET, Argentina The damage caused by snow avalanches to property and human lives is underestimated in many regions around the world, especially where this natural hazard remains poorly documented. One such region is the Southern Andes, where numerous settlements are threatened almost every winter by large snow avalanches. On September 2002, the largest tragedy in the history of Argentinean mountaineering took place at Cerro Ventana, Northern Patagonia: nine persons were killed and seven others injured by a snow avalanche. In this paper, we combine both numerical modeling and dendrochronological methods to reconstruct this event. Using information provided by local governmental authorities and compiled in the field, the avalanche event was numerically simulated using the avalanche dynamics programs AVAL-1D and RAMMS. Avalanche characteristics, such as extent and date were determined using dendrochronological techniques. Model simulation results were compared with documentary and tree-ring evidences for the 2002 event. Our results show a good agreement between the simulated projection of the avalanche and its reconstructed extent using tree-ring records. The main goals of this study are (1) to provide the first calibration of numerical avalanche models for the Patagonian Andes and (2) to highlight the potential of Nothofagus pumilio tree-ring records to reconstruct past snow-avalanche events in time and space.