Simulating avalanches to enhance the safety of Chilean copper miners

On 8 August 1944, 102 miners lost their lives in an avalanche accident that destroyed the living quarters of a Central Andean copper mine. This accident serves as an example of many similar disasters that struck mines during the past century throughout the world.

The mining industry has changed dramatically over the last century.  Miners no longer live within the mines, but travel back and forth in shifts.  Access roads are exposed to the danger of avalanches and represent a major hazard. When these roads are closed, the mine operators incur severe financial losses. Severe snowstorms can disrupt mine activities for several days causing miners to be trapped within the mine, often without food in exposed areas. The safety authorities would therefore like to know with if avalanches are capable of reaching access roads or other buildings where miners reside.  They need methods to determine when snow masses are likely to be released and, if the road is cut, how quickly can it be cleared.

The Codelco Andina mine in Chile, one of the world's largest copper mines, engaged the SLF to produce a forecasting tool tailored to meet these needs. A PhD candidate developed a model which, for the first time, can calculate the run-out distances of wet snow avalanches from the prevailing snow conditions. It is based on numerous observations of mostly fairly small wet snow avalanches that have occurred in the vicinity of the mine. The model is implemented in the RAMMS software package.  In order to calibrate the computer model for their practical purposes, the Chilean safety authorities must enter a variety of data, including the terrain features using a high resolution digital elevation model. Equally important is current information concerning the structure or bonding of the snowpack as well as its temperature and water content, not only in the starting zone, but also along the avalanche path.

The SLF has already been testing the model in the Andina mine for several winters. In view of the highly promising results, the safety authorities have now integrated the model in their everyday operations.