Journal of Geophysical Research “Very high-elevation Mont Blanc glaciated areas not affected by the 20th century climate change"
The research was conducted by six scientists from leading agencies and departments in France and Switzerland that deal with hydrology and glaciology. The research was funded by Observatoire des Sciences de l’Univers de Grenoble (OSUG), the European Programs ALPCLIM and CARBOSOL, and by the city of Chamonix Mont-Blanc.
Vincent et al. collected a variety of datasets that could help them understand how the high-elevation glaciers of Mont Blanc were impacted by variations and trends in climate. Among other findings, they found that the mass balance of the glaciers is strongly controlled by precipitation, not temperature.
Vincent et al. state "The most striking features of these figures are the small thickness changes observed over the 20th century. For both areas, thickness variations do not exceed ±15 m. The average changes are +2.6 m at Dôme du Goûter (please note that this glacier is growing) and -0.3 m (-12 inches) at Mont Blanc.
"Considering the uncertainty interval, i.e., ±5 m, it can be concluded that no significant thickness change is detectable over most of these areas". "All these results suggest that the SMBDôme du Goûter and Mont Blanc did not experience any significant changes over the 20th century."
"Geodetic measurements carried out in 1905 and 2005 on the highest ice fields of the Mont Blanc range indicate small thickness changes and show that these very high-elevation glaciated areas have not been significantly affected by climate change over the last 100 years."
"In any case, this study reveals that the very high-elevation ice fields in the Mont Blanc area have not been affected by the climate warming.
"The 20th century climate warming affected the atmospheric temperature in the Alps by +1EC. However this change did not significantly affect the ice deformation rate in the high-altitude ice fields since the ice temperature remains far below the melting point and therefore keeping the glacier frozen to its bed."
Basicamente los glaciares del Mt Blanc de gran altitud no se han visto afectados por el calentamiento registrado en la zona; de 1ºC en los últimos 100 años. Los estudios hechos por gravimetria desde 1905 muestran una variación de en el Dome du Goutier de +2,6m mientras que en la cima del MontBlanc ha sido de -0,3m.
Como la incertidumbre del estudio es de 15m no hay variaciones concluyentes.
Tb el estudio muestra que los glaciares de esta zona están muy fuertemente afectados por el regimen de precipitación.
Saludos