Threats to Chile's rock glaciers

Daniela Estrada in IPS: A new government policy on glaciers adopted by Chile "is a step forward, but it doesn’t resolve all of the problems," German geographer Alexander Brenning, who blames mining companies for threats to this South American country’s rock glaciers, told IPS. An assistant professor of geography at the University of Waterloo in Canada, Brenning spoke with IPS after giving a lecture this week on the little-known rock glaciers to geology students at the University of Chile, who had specially invited him.

The expert drew attention in Chile last year after the results of studies he carried out were reported locally. His research in this country found that three large mining companies were affecting several square kilometres of rock glaciers by building roads and other infrastructure and piling sterile material on them.

Brenning specifically pointed his finger at the Andean Division of the state-run National Copper Corporation (CODELCO), the Los Bronces mine operated by the London-based Anglo American mining giant, and Los Pelambres, a Chilean mining company.

In his lecture Wednesday, Brenning explained that rock glaciers are important natural sources of frozen water that contribute to the availability of water supplies during the southern hemisphere summer. And they are threatened not only by mining operations, but by climate change as well, he said.

Under the top layer of rock, these glaciers are 40 to 60 percent ice, he said. Because it takes thousands of years for rock glaciers to regenerate, and since they are unstable, moving several centimetres a year, building infrastructure on top of them is not recommendable, said Brenning.

Brenning, who combines analysis of satellite images with aerial photos and field work, believes rock glaciers are found mainly in central Chile, and that their total surface area is approximately 500 square kilometres. According to his research, the three mining companies have affected 3.2 square kilometres of rock glacier, encompassing between 23 and 35 million cubic metres of water, over the last decade, he said, pointing out that part of that area was literally removed….

NASA photo of Bernardo Glacier, the Southern Patagonia Ice Field, in Chile. Not a rock glacier, but it is in Chile.