Stories of Alpine neoglaciation: Scientific framings by isotope datings and scenarios of rapid climate change

Mythological narratives of reglaciation are found in story collections all over the Eastern Alps. For glaciers like the Marmolada (IT), Übergossene Alm, Gurgler Ferner (AT) and many others, almost identical story lines describe heavy thunderstorms during summer that covered fertile alpine pastures with large amounts of snow. Snow that did not melt in the following years, burying huts, hay storage barns and people. Snow heights could range from buried cooking huts, which can be as low as 1.5 m to hay storage barns of several metres height. Interestingly, there is still an ongoing discourse whether Ötzi, the ice man, was covered by such a type of event after dying on snow-free ground, based on radiocarbon dating and pollen analysis, as well as on an analysis of his last meal. As historical pendant to prehistoric findings, the written history of mining activities, together with dendrochronological findings, shows that mining sites were buried under snow and ice during the Little Ice Age.

From a glaciological perspective, the potential course and pace of reglaciation is significant for several reasons. First, the variability of snow cover and extreme events is important for the interpretation of Alpine (and potentially discontinuous) ice cores. Second, the chance of an Alpine reglaciation at the end of this century is small, but cannot be ruled out, so that it is vital to understand the potential course and role of mean and extreme precipitation events. Moreover, finding out whether those myths could be tied to volcanic events would help to capture the potential information that has survived for centuries in oral tradition. A prominent and recent example of climate events alive in oral tradition is the story of 1816, the year without summer. Third, in terms of hazard research, events as described in the mythological narratives could highlight major issues for modern mountain societies.

Geoarchives, such as ice cores, dendrochronology and radiocarbon dating, can help to verify hypotheses derived from the myths by constraining a potential timing. Datings of the oldest ice of Weißseespitze and Schladminger Glacier confirm a reglaciation of the Eastern Alps, with the timing depending on elevation. In addition, radiocarbon dating of organic material close to recently deglaciated summits points to potential periods of reglaciation, the latest one occurring at lower elevations just before the Little ice Age. By that time the Alps had already been converted to Christianity, so the religious framing with reference to Christian festivities could fit that outermost and recent layer of those stories.

In the light of the modelling scenarios pointing to a potential sudden change in Atlantic ocean currents, with rapid climate changes for Northern and Central Europe, the key features of the myths could reoccur: Heavy thunderstorm events during summer in warm air bringing in a cold front with extreme precipitation, followed by a lasting drop in summer mean temperature or decreased solar radiation, with a snow cover that fails to melt for years. Myths like that could offer a potential synoptic scenario related to global climate change.