April 12, 2011

Maladeta Glacier retreat, forecast not to survive

Posted by Mauri Pelto

Maladeta Glacier is located amongst the highest peaks in the Pyrenees and is on same mountain massif as the largest glacier in the Pyrenees, Aneto Glacier. Chueca et al (2007) noted that the glacier has retreated significantly from 1935 to 1957 and 1981-2010. From 2001-2005 the glacier retreated 120 m. The glacier in 2008 was 700 m long. They also noted that Maladeta Glacier has lost 70% of its area from 1850 to 2007, from 1.5 square kilometers to 0.45 square kilometers. The glacier is seen below in an image from the WGMS. Miguel Arenillas from the Polytechnic University of Madrid has reported thee mass balance from 2001-2009 to the World Glacier Monitoring Service was -8.4 meters. Given the estimated glacier thickness of 30-40 meters, this loss in the last decade represents approximately 25% of the glacier lost in a single decade. The behavior follows that of other Pyrenees glaciers, in 2004-2005 15 of 16 glaciers observed and reported to the WGMS retreated.Chueca et al (2007) identified that these changes have been forced by a reduction in the snowfall contributions and increase in the maximum temperatures during the past few decades in the Pyrenees. The 2008 Google Earth image indicates a glacier almost devoid of snowcover. It is also evident in the Google Earth images and a view of the glacier from below the terminus, that the glacier is quite thin in the lower reaches and has very limited crevassing. Both suggest a glacier with minimal movement. In the first image from 2008 the lower margin of the glacier is indicated by a blue line.The lack of a substantial accumulation has led to the large negative mass balances. To survive a glacier must have a persistent and consistent accumulation zone. The lack of a consistent accumulation zone on Maladeta Glacier will lead to the total loss of this glacier in the next 20-30 years. Given that at least 16 glaciers have disappeared in the last thirty years in the Pyrenees, it will not be the exception.