Wednesday 13rd September 2017, the surveyors unveiled the new official measure of Mont Blanc.
The highest mountain in the Alps and the highest in Europe is 4808,72 metres tall.
According to Le Parisien, the height of Mont Blanc is checked every two years. The last time they measured the mountain was in 2015.
According to the data, since then there's only been a lost in height of 1 centimeter. The altitude of the Mont Blanc varies continuously due to the intensity of the winds, the precipitations and the footsteps of the mountaineers. It can either grow or shrink.
A complicated ascent
To perform the 9th Mont Blanc measurement campaign, the glaciologists must first ascend the Mont Blanc.
Nicolas Cornier, chartered surveyor at La Roche-sur-Foron (in Haute-Savoie) said that "The measure was made yesterday morning, Wednesday 13rd September 2017 and the weather conditions begun to be quite complicated, after the ascent of the Mont-Blanc by the normal route".
Measuring the Altitude of Mont Blanc
The measurements at the summit normally last about 1 hour and 30 minutes. But this time, they were made "a little quicker than usual to allow themselves the time to descend the summit," he explained.
"At the top of of Mont-Blanc, they installed receivers from Leica Geosystems, small cupolas from 15 to 20cm in diameter, located on a stick planted in the snow: they record the GPS signals emitted by the satellite and these signals are corrected by the Teria network to obtain measurements to the nearest centimeter" told the surveyor.
It is a question of calculating the volume of ice covering, the rocky peak which culminates at 4,792 m. The stronger the precipitation and the lower the wind, the more snow accumulates at high altitudes, causing the increase of the ice cap which covers the peak.
According to Le Parisien, also for the second time this year, the surveyors did some late spring surveys or a «winter outing» in June.
Nicolas Cornier pointed out that "The Mont Blanc was 4808,06m. One expects rather the contrary, that the summit is higher at the end of the winter".
"But this winter was so cold that the snow didn't adhere to the top and did not accumulate, and this summer the snow was more sticky with a lower isotherm," he said.
Next measurement campaign will be launched in 2019, when a new altitude for the Mont Blanc is to be announced.
