The broadest glacial area of Trentino
The Adamello Brenta Nature Park currently hosts the broadest glacial area of Trentino, comprehending 41 glaciers in its territory. In the Brenta Group there are 17 small glaciers. During the past forty years, numerous glacial tongues have disappeared and the total surface of the glaciers has shrinked of at least a third. On the Presanella, that hosts 7 glaciers, the retreat has been less consistent, same as in the Adamello Trentino, that encloses 17.
Despite their retreat, the glaciers are still extremely imposing, especially the Mandrone hanging glacier: the major glacier of the Italian Alps, but also the conterminous Lobbia and Lares glaciers. The wonderful hanging glaciers on the southern ridge of the Presanella, all located in the Park territory, are exceptionally spectacular.
Ghiacciaio Adamello-Mandrone; credits: Unknown.
Twenty Thousand years ago
The glaciers of the Park are constituted by the remains of the enormous mass of ice that, between 18,000 and 20,000 years ago, used to cover the entire Alps. At that time, only the peaks of the highest mountains emerged from the icecap, whose thickness was around 2000 m in the area of the middle Val d’Adige and 1000 m in the Garda territory.
The receding phase
The receding phase, consequence of the climate change, firmly started about 15,000
years ago and continued until 6000 BC (“Late-glacial” period), but it was interrupted by various phases of climate worsening that brought to momentaneous expansions of the glaciers. The mild “post-glacial” period followed the “late-glacial” period and lasted until about 2500 BC.
During the Bronze Age there was another cold period, followed by a long heat wave that lasted until 1600 AD and that caused the retreat of the hanging glaciers at altitudes a lot higher than the current ones. Therefore, areas that today are still occupied by glaciers, were freed from the ice at that time. Between 1500 and 1850, during the so-called “Little Ice Age”, the glaciers went through a new phase of firm expansion. Then their retreat began, although irregular, and it’s still going on nowadays causing a substantial shrinkage of the glacial tongues.
For example, the Lobbia and Mandrone glacial fronts have been retreating for more than 2 km since the middle of the 19th century and they are currently located 800 meters higher compared to their previous position. This process occurred very rapidly during the last decades, to the extent that numerous glacial areas separated and many more disappeared.
The study of glaciers
The widespread interest toward the world of glaciers can be perceived when visiting the Adamello “Julius Payer” Studies Center, a glaciological studies center set up by Sat at 2429 m of altitude, not far from the Mandrone mountain hut. The center, inaugurated in 1994, provides its visitors with an introduction on the basic principles regarding the glacial environment.
From the glaciers to running water
From the glaciers, precious reserves of pure water, numerous and impetuous watercourses originate, often generating spectacular waterfalls. For this reason, there are significant differences between Adamello-Presanella and Brenta. The first mountain chain hosts, in fact, numerous glaciers and snowfields, that feed the watercourses with their summer melting. On the other hand, in the Brenta group the glaciers have been reduced to extremely small areas. Moreover, the magmatic rocks of Adamello-Presanella are nearly waterproof and the water flows over them, whereas the calcareous-dolomitic rocks of Brenta are extremely permeable and water often leaves the surface to disappear in their depths, originating interesting karst phenomena, among which an example is provided by the Vallesinella waterfalls.
Some of the glaciers of the Park: