Regional climatic variations and tree-ring based avalanche reconstructions in the Patagonian Andes

CASTELLER, A., VILLALBA, R., STÖCKLI, V.

Corvallis, Oregon, EE.UU.

Conferencia; PAGES 3rd Open Science Meeting; 2009

PAGES

The occurrence of avalanches is largely determined by meteorological conditions such as the amount and type of precipitation, air temperature, wind speed and direction, and solar radiation. In forested areas, trees growing along avalanche tracks allow reconstructing past avalanche events with year accuracy. In the Patagonian Andes, the subalpine forests dominated by Nothofagus pumilio are commonly affected by avalanches. In this study, we reconstructed past events at 11 avalanche tracks located on the Loma de las Pizarras (49°18’ S, 72°57’ W), Parque Nacional Los Glaciares, Argentina. A total number of 67 avalanche events were reconstructed; the first of these events dates back to yr 1875. In order to determine the relationship between climatic variations and avalanche dates, precipitation and temperature records from nearby meteorological stations were compared with the avalanche records using the Superposed Epoch Analysis. Years with relatively high avalanche activity are significantly correlated with high winter precipitation (May to October). We anticipate that predicted warmer temperatures in the Andes during the 21th century will affect both the frequency and extent of snow avalanches.