• Corpus ID: 49214133

Back-Analysis Modelling of the Catastrophic Avalanches in Sewell, Central Chilean Andes

@inproceedings{Janeras2013BackAnalysisMO,
  title={Back-Analysis Modelling of the Catastrophic Avalanches in Sewell, Central Chilean Andes},
  author={Marc Janeras and Pere Oller and Rodrigo Garc{\'i}a Arancibia and Judit Pons and Olga Costa and Danilo Asensio and Santiago de Chile},
  year={2013}
}

• M. Janeras, P. Oller, +4 authors S. Chile
• Published 7 October 2013
• Geography

In the Chilean Andes, avalanche risk is often related to mining industry, due to its pres- ence in this mountain range, comparing to other activities. A paradigmatic case is El Teniente mine, the largest underground copper mine in the world, located at southeast of Santiago de Chile, VI Re- gion of Chile. Although the most part of mineral extraction is underground, a lot of facilities and asso- ciated devices are placed on surface, like the town of Sewell at 2.100 m a.s.l., that grew up to 15.000 inhabitants during the first half of the XX century, increasing the risk with the exposure. As corre- sponds to the climate in the central Chilean Andes, Sewell has a highly variable precipitation regime, depending on the ENSO effect, what determines the conditions for major avalanches. Taking into con- sideration all available information (photographs, chronicles, nivological data) an accurate scenario was recreated to fit each 1914, 1926, 1941 and 1944 catastrophic events. Two of them are wet dense flow, and the other two are dry snow avalanches with a powder part. It is clearly seen the different be- havior at the run-out zone where deflection is imposed by the main valley and run-up occurs for the powder. To perform the dynamics calculation, Aval-1D and RAMMS software were used on the basis of the Voellmy - Salm formulation. The friction parameters are reviewed and, from these and other experiences, a modification for the altitudinal limits is proposed.