June 30, 2015

Disintegration of Pramecou Glacier, France

Posted by Mauri Pelto

Pramecou Glacier is on the Dome de Pramecou above the Grande Motte Glacier, which is a key portion of the Tignes Ski area in France. The Grande Motte area is open for summer skiing this year from June 27th to Aug. 9th. The glaciated landscape in this area is changing dramatically, Gardent and Deline, (2011) noted a 33% loss in glacier area since the 1960’s. The Tignes Ski area has responded by adding snowmakers for the lower portion of Grande Motte Glacier. In the hot summer of 2015 the melt is still causing issues for skiing at Tignes. Here we examine the impact on Pramecou Glacier and Grande Motte Glacier.

STGM Ski été automne 18
Grand Motte Summer Glacier Ski Map
pramecou map
Topographic map of area.

In 2006 the Pramecou Glacier had separated into three sections that did not retain snowcover, each outlined with black dots in Google Earth image below. This had been the case in 1999 and 2003 as well losing all of the snowcover.   In the 1988 Landsat image below the Grande Motte Glacier west terminus is at the green arrow at the top of a steep slope that falls to the Rosolin Glacier below.  The yellow arrow is the east terminus ending at the base of a rock knob yellow arrow.  Points A and B are along the margin of the Grande Motte Glacier.  The pink arrow indicates the Pramecou Glacier that consists of the larger two segments still merged. In 1999 the Landsat image indicates the loss of snowcover on both glaciers and the near separation of the two main Pramecou sections. The Grande Motte terminus has not retreated noticably yet. The 2002 Landsat image indicates the west terminus of the Grande Motte Glacier has retreated from the green arrow.  There is only modest thinning and marginal change at Point A and B.

The large change occurs between 2002 and 2014.  By 2014 both the east and west terminus of Grande Motte have retreated from the yellow and green arrows.  Each has retreated 200-250 m since 1999.  The larger change is the thinning evident at Point A and B. At Point A a large area of rock has been exposed extending from the north margin well into the glacier.  At Point B thinning has exposed a much wider ice free belt along the northern margin of the glacier.  At Point C the northeast ridge of  Grand Motte bare rock area is expanding.  It is clear the Pramecou Glacier will quite soon be lost.  The Grande Motte Glacier is thinning along its upper margins and is losing its snowcover by summer’s end, both are signs of a glacier that cannot survive (Pelto, 2010).  That is unless the Tignes ski area takes greater measures to preserve the glacier. This trend is following the behavior of Glacier Blanc and Mer De Glace. Those larger glaciers are not currently threatened, as these are with melting away.

pramecou image
2006 Google Earth image of Pramecou Glacier segments

Pramecou 1988
1988 Landsat image

pramecou 2014
1999 Landsat image

pramecou 2002
2002 Landsat image

pramecou 2014real
2014 Landsat Image

pramecou ge
2006 Pramecou Glacier and Grande Motte Glacier