Everyday in Santiago we look up at the majestic snow covered Andes. But from time to time we are roughly reminded that these mountains which loom above the city can become dangerous.
This week a large part of the mountain some 40 miles away from the city gave way. This is how the geologists explained it: The Andes in this area that points north receive very little or no rain during the summer except during what is called the “Bolivian winter”. Then humid air blows down from Brazil and Argentina. This causes rain and snow in the high desert, particularly in the north of Chile, where there is no rain at all during the year. Here in Santiago there are about 14 inches of rain in a normal year, all of it falling in the winter.
This week heavy rains of the Bolivian winter fell at high altitudes above the city. The rain mixed with the snow and the dry mountainside. Then the mountain side gave way. This happened in two locations in Chile, the other some 1,000 miles to the north closing the beach there. A couple of people were able to catch this moment with their cell phone cameras. The images are remarkable as you can see boulder floating down the river in the YouTube video shown above. A river of pure rock and boulders came racing down the hillside. It was as if the entire Maipo River had been replaced by rock. A few dozen foreign tourists had gone to visit the geothermal baths on the uphill side of the river at Cajon de Maipo and had to be lifted out by helicopter.
The water purification plants were overwhelmed by all the dirt and rocks. They had to shutdown the intakes to their plants. The result was a million people were suddenly left without water with which to wash their clothes, cook food, and bathe. This was called an “act of God” by the labor minister so employers were not obligated to pay their employees as their businesses closed. Two days later the city is supposed to have water once again, when the river clears.
The Spanish word for this geological catastrophe is “alud” or “aluvion”. In English it might be called a “lahar” but that is usually associated with volcanic activity which melts snow. There have been worse lahars. In Colombia a dozen years ago a lahar killed 20,000 people in mud and rock which quickly raced onto the city below and formed concrete forever entombing people in their homes. Here in Santiago there have been worse including one in 1993 that swept through the part of the city called Macul. Here is a video of that. Fortunately there was no loss of life this time.