“Dendrochronology as a tool to validate avalanche numerical simulations in the Patagonian Andes”.

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

Santiago de Chile

Conferencia; 4th Alexander von Humboldt International Conference The Andes: Challenge for Geosciences EGU Tropical Conference Series.; 2008

EGU European Geosciences Union

Dendrochronology as a tool to validate avalanche numerical simulations in the Patagonian Andes A. Casteller (1,2), M. Christen (2), R. Villalba (1), H. Martínez (3), V. Stöckli (2), J. C. Leiva (1) and Perry Bartelt (2) (1) Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales, CONICET, Mendoza, Argentina, (2) WSL, Swiss Federal Institute for Snow and Avalanche Research,  Davos Dorf, Switzerland, (3) Facultad de Ingeniería UNCuyo, IDEPRN, Mendoza, Argentina (casteller@lab.cricyt.edu.ar / Fax: +54 261 52444201 / Phone: +54 261 5244205) Snow avalanches cause severe property damage and loss of life in many regions around the world, especially where they remain 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,  when nine persons were killed and seven others injured by a snow avalanche.  In this study, we combine both numerical modeling and dendrochronological methods to reconstruct this event. Using information provided by local authorities and  compiled in the field, the avalanche event was numerically simulated utilizing the  avalanche dynamics programs AVAL-1D and RAMMS. The extent of the event was  also reconstructed using dendrochronological methods. 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  dendrochronologically-reconstructed extent. Moreover, the tree-ring records provided  a chronology of other undocumented avalanche events that have occurred at the site. The main goals of this study are (1) to provide the first calibration of avalanche numerical  models for the Patagonian Andes and (2) to highlight the potential of Nothofagus  pumilio tree-ring records as a tool for reconstructing past snow-avalanche events in  time and space.