In September 2013 a group of 14 people put up with an amazing task – they decided to scan the highest mountain in Europe – Mont Blanc. It was a formidable challenge for both the team and surveying equipment, that had to face freezing temperatures and gusting winds.
Mont Blanc meaning “White Mountain”, is with 4,808 m height above sea level the highest mountain in the Alps and the highest peak in Europe west of Russia after the Caucasus peaks. It lies in a mountain range called the Graian Alps, between the italian region of Aosta Valley, and french regions Savoie and Haute-Savoie. From the summit of Mont Blanc on a clear day, the Jura, the Vosges, the Black Forest and the Massif Central mountain ranges can be seen, as well as the principal summits of the Alps. The Mont Blanc massif is popular for many sport activities such as mountaineering, hiking, skiing, and snowboarding.
Mont Blanc’s summit is a thick, perennial ice and snow dome whose thickness varies depending surrounding conditions. No exact and permanent summit elevation can therefore be determined, though some attempts of accurate measurements have been made on specific dates. For a long time its official elevation was 4,807 m. In 2002, the IGN and expert surveyors, with the aid of GPS technology, measured it to be 4,807.40 m.
Considering a relatively big difference between height measurements, the elevation of the mountain has been measured every two years. The summit was measured again in 2005, and the results were published on 16 December 2005. The height was found to be 4,808.75 m, 30 cm more than the previous recorded height. The rock summit was found to be at 4,792 m, some 40 m west of the ice-covered summit. Later on in 2007 the summit was measured at 4,807.9 m and in 2009 at 4,807.45 m. In 2013 the summit was measured at 4,810.02 m and in 2015 at 4,808.73 m.
The team of 14 climbers, that undertook this difficult task, included a number of surveyors and their technical partners: Covadis (Géomédia), Teria (Exagone) and Leica Geosystems. The team was accompanied by guides and photographers. Farouk Kadded, who represented Leica Geosystems, was responsible for measuring the elevation and shape of the ice cap of Mont Blanc. He is Product Manager at LGS France and an experienced climber who founded the partnership that was formed with the surveyors from the Upper Savoy region. Farouk has taken part in the expedition since 2001 and explained why 2013 presented an opportunity to add a new technical dimension to the expedition. The team decided to make the first 3D-laser scan of the shape and volume of this legendary glacier using the Leica’s newest multistation to date – Nova MS50.
Leica Nova MS50 represents the peak offer in today’s total station market. It has something called mergeTEC, a technology that allows combinations of total station and 3D laser scanning technologies. It merges different processes in the fields of total station measurements, digital imagery, 3D laser scanning and GNSS positioning. mergeTEC takes care of software and hardware synchronisation, allowing scans to be tied into total station measurements – perfect for managing complex 3D data. Some of the more ‘traditional’ surveying stats about Leica MS50 can be found in a table bellow.
The 2013 expedition proved that the current elevation of Mont Blanc is 4,810.02 m, which is 42 cm less than in 2011. The actual height of the rock summit is 4,792 m, however the snow covering the peak varies in thickness, meaning actual summit’s altitude anywhere is anywhere from 15 to 20 m higher than the rock summit. Géomédia calculated the volume of the ice cap covering the rocky summit, which resulted in 20,213 m³. This company also produced a 3D animation from the scan data as well. Results, gathered from this expedition, could in the future help researchers determine possible changes to the ice cap caused by different parameters, such as global warming. The model of glaciers snow cap was determined by close to 100,000 points with millimeter accuracy and it represents a great technical achievement.
sources: http://leica-geosystems.com/case-studies/surveying-and-engineering/scanning-the-top-of-europe, http://www.leica-geosystems.us/en/Leica-Nova-MS50_103592.htm,http://c.ymcdn.com/sites/www.njspls.org/resource/resmgr/Docs/LASERSCANNING.pdf ,https://en.wikipedia.org/wiki/Mont_Blanc, http://www.directsurveystore.com/products.php?product=Leica-Nova-MS50-1%22-R2000-MultiStation