The expedition
As Alpine glaciers thin and retreat they expose slopes that are thought to go through a period of more frequent or larger landslides before settling to a background rate: permafrost thaws inside the rock walls, valley sides lose the buttress of ice, and rain destabilises the loose debris left behind. How large and how often such failures are, and how they relate to the former extent of the ice, was poorly known because the catchments are remote and unmonitored. The Grand Alpine Tour set out to measure it. The team were three geographers from Northumbria University in Newcastle: Mark Allan, a PhD researcher who held the award, Dr Mike Lim, and Thomas Shaw, a glaciology PhD student whose own study site was the debris-covered Miage glacier. They won the 2014 Land Rover Bursary, administered by the Royal Geographical Society (with IBG), which brought a grant and a fully equipped Defender 110 — a new white left-hand-drive 110 XS station wagon, VU14 XUG, registered in April 2014 — to carry the survey gear and get it to the ends of Alpine valleys.
The method was Structure from Motion: a hexacopter unmanned aerial vehicle photographed the slopes above and around each glacier in overlapping passes, and the images were resolved into three-dimensional models. Repeated surveys could then be overlaid to find where rock had moved and to calculate the volume of each failure, and the results set against the Society's archive of historic Alpine maps, paintings and photographs to relate the changes to past ice extents. An artist travelled with the team to record the landscapes as the Grand Tourists of the eighteenth century had, and the project was framed as a modern Grand Tour of the mountains.
The principal study sites were the Argentière, Mer de Glace, Bossons and Bionnassay glaciers on the French side of the Mont Blanc massif, the Miage and Pré de Bard glaciers on the Italian side in the Aosta Valley, and the Rhône glacier in the Swiss Valais. The Argentière had retreated a kilometre between 1870 and 1967 and then, in the five years before the visit, rapidly to the top of a steep step; the Mer de Glace, the longest glacier of the western Alps at 12 km, had lost 2.3 km since the Little Ice Age and its lowest 12 per cent was stagnant; the Bossons terminus had risen from 1,050 m in 1900 to nearly 1,400 m; the Miage had thickened in the 1970s and 1980s almost to the top of its moraines and then thinned at an accelerating rate; the Pré de Bard had broken in two at the end of the 2012 summer; and the Rhône, the largest glacier of the Alps at the last glacial maximum, had retreated 3 km up its valley. The RGS describes the journey as six thousand miles through some of the Alps' toughest terrain, from the UK to Italy through France, Austria, Switzerland and Slovenia.
The field report written for the Society's schools programme showed the first 3D models in processing and promised change-detection results to follow; the expedition became three RGS lesson modules on the Grand Tour and tourism, on fieldwork design in the Alps and on the landslides of the Aosta Valley. Where the Defender went in Austria and Slovenia, and the order in which the sites were visited, are not recorded in the sources found. The Defender went on to be rebuilt by Land Rover Special Vehicle Operations as the Trail by Fire mobile volcano observatory for the 2015 bursary in the Andes.
