The Little Ice Age in the Massif of Mont Blanc

Abstract

CLIMATIC FLUCTUATIONS in Europe, since medieval times, have had some interesting geographical consequences, especially in mountain areas.1 The history of glacial behaviour is one of the main lines of evidence available for their investigation. As accumulation and ablation vary, so glaciers must advance and retreat. But the response of a glacier to a particular climatic oscillation depends not only upon the nature and duration of the meteorological changes involved but also upon the character and position of the ice mass and the shape of its bed. Data concerning individual glaciers can therefore be misleading, and it seems safest to trace the glacial fluctuations of a whole massif. Individual anomalies are then recognizable, and some picture of the nature of the impact of the waxing and waning of glacial tongues upon the life of a mountain people is also more likely to emerge. Yet this approach has been surprisingly neglected. The advance of glaciers in the northern hemisphere to more forward positions, which were generally maintained during the seventeenth and eighteenth centuries and a large part of the nineteenth century, was certainly a wide-spread phenomenon; so is the current retreat to positions comparable with those of the mid-sixteenth century.2 This period of glacial enlargement is now often called the Little Ice Age. Not surprisingly, the scale and timing of the oscillations involved do not seem to have been everywhere the same, even in Europe, but full appreciation of the extent of these differences must await the completion of a sufficient number of detailed regional studies. An unusual variety and volume of evidence is available about the fluctuations of the glaciers of the massif of Mont Blanc. Although cartographic coverage was poor until the nineteenth century, and although as late as 1863 A. Adams-Reilly3 found it 'strange that the chain of Mont Blanc should be the most visited and at the same time the worst mapped portion of the Alps' (Note I), a wealth of good maps has since appeared (Note II). The glaciers have been the subject of well over a hundred papers, as well as a number of books and monographs.4 Several of these give valuable systematic accounts of the oscillations of particular glaciers for various periods5 or even of all the glaciers of a particular national sector of the massif for the whole of the Little Ice Age.6 Corbel in his recent paper on glaciers and climate in the Mont Blanc massif7 was naturally able to devote only a few pages to the fluctuations of the last few centuries. E. Le Roy Ladurie,8 in his very interesting study of climate and harvests of the seventeenth and eighteenth centuries, drew particularly on data from the Chamonix valley, but was not concerned either to assemble the overall data for this one region, or to deal with more recent events.