For the first time since 2001 the mass balance of the Glacier Blanc in the Ecrins range is positive. It has gained 21cm (water equivalent) in the last year. However the snout remains very thin and is vulnerable to another hot summer such as that of 2003.
Before the climate change deniers break out the Champagne it is important to take a closer look at the figures. The mass balance is the difference between snow accumulated in winter and snow and ice that melts during the summer. If a glacier retreats it can actually re-establish equilibrium without any change in climate if the accumulation zone is at significant altitude. This seems to be the case with the Glacier Blanc which lost 210cm in 2003, 130cm in 2005, 80cm in 2006 and 44cm in 2007.
This year’s positive figures are down to good snowfall from mid March following a poor winter and a cold July. The snout of the glacier is still retreating. Five meters in 2008. The glacier has lost between 20 to 30 meters depth over the last two decades between 2700 and 3000 meters.
http://en.wikipedia.org/wiki/Glacier_mass_balance
http://www.vallouise.info/glaciers/glaciers-20.htm
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