March 9, 2017

Cavagnoli Glacier, Switzerland Fading Away

Posted by Mauri Pelto

Google Earth image of Cavagnoli in 2010 and a Sentinel 2 image from Sept. 9  2016.  Ice masses are numbered.  No retained 2016 snowpack, note the lighter colored snow on the upper Basodino Glacier

Cavagnoli Glacier (Ghiacciaio dei Cavagnöö) drains south into Lago dei Cavagnoli (Lago dei Cavagnöö), which is impounded by a dam that is 111 meters high.  The glacier like its neighbor Basodino Glacier  is in the Ticino River watershed and supplies the Robiei/Cavagnoli Hydropower system. The Cavagnoli Hydropower plant can provide 28 MW of power. The Swiss Glacier Monitoring Network noted that glacier area in 1973 was 1.36 square kilometers, when the glacier was a single ice mass.. The Swiss Glacier Monitoring Network has observed the annual retreat of this glacier since 1980, total retreat up through 2013 is 378 m of the main glacier.  The top of the glacier has also been retreating this is a symptom of a glacier that will not survive (Pelto, 2010). Huss and Fischer (2016) indicate that the majority of the small alpine glaciers, less than 0.5 square kilometers will disappear in the next 25 years.

This glacier has no accumulation zone in 2003, 2005, 2007 or 2010 Landsat and Google Earth imagery. The glacier itself by 2010 had separated into five separate ice masses that are each melting quickly away.  The glacier as viewed from below and from directly above in Google Earth Imagery indicates a thin glacier with few crevasses.This has become a reoccurring pattern for this glacier, and also is a sign of a glacier that cannot survive.   In 2010 Google Earth imagery the largest ice mass was 0.4 square kilometers and none of the ice masses appear destined to survive. In 2016 the Sentinel 2 image indicates there are four remaining ice masses, with a combined area of 0.3 square kilometers, with the largest ice mas now at less than 0.2 square kilometers.  There is no retained snowpack in the 2016 Sentinel image either. On the main ice mass there is a meltwater stream from the top to the bottom of the glacier indicating that even the top of the glacier is usually snow free by summer’s end. This glacier is a small relic of its former mapped extent.   The glacier will not persist, but is also an example that even small glaciers in poor health do not disappear quickly.