Fragile and in retreat: all there is to know about Italian glaciers

Fragile and in retreat: all there is to know about Italian glaciers

Fragile and in retreat

The fatal detachment of the glacier at Punta Rocca della Marmolada, causing the death of 7 hikers while another 13 are still missing, was not foreseeable. Climatologist Luca Mercalli wrote it: he reiterates it to Guglielmina Diolaiuti, professor of physical geography and geomorphology at the Department of Environmental Sciences and Policies of the University of Milan:

"This event was not easily predictable, it must be said, however, that in the context of generalized collapse of glaciers due to climate change and the scorching temperatures of the summer 2022 it is not advisable to venture on the glaciers nor, above all, to remain on their surface in the central hours of the day when the high heat creates dangerous effects for stability ".

What can already be predicted, however, is that due to the average temperatures of recent years, Alpine glaciers below 3,500 meters are destined to disappear within 20-30 years. It is the result of a progressive instability of the Alpine system, given that between 2000 and 2020 in this area there were 508 landslides and glacial instability events at an altitude of less than 1500 meters, caused by climate change. The point where the tragedy occurred was around an altitude of 3,200 meters.

Marmolada, the reduction of the glacier and the causes of the collapse According to updated studies about 40 years ago, the surface of the Marmolada glacier had an area of ​​2.4 km²: today it measures less than half, or just 1 km² , above all because of the seracs that constantly collapse. Therefore, considering that according to Legambiente there was a reduction in the volume of the glacier greater than 85% which took place between 1905 and 2010 and a thickness of the forehead, which has gone from almost fifty meters at the beginning of the last century to a few meters today. And finally, that in just ten years the Marmolada glacier has reduced its volume by 30 percent. These data, read together, may therefore indicate that the glacier reduction is incremental.

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If we think instead of the causes of the tragedy of July 3, Professor Diolaiuti has a partially different explanation from the one shot on many media: “From the information available at the moment, it seems that a large portion of ice has been detached at the Marmolada. This portion of the glacier would not have been part of a serac, as has been said by many, but would instead be an integral part of the glacial apparatus which broke off following the deepening and widening of a crevasse ". The evidence would lie in what remains in the wall that has detached, where "only the lower portion of this ice wall appears blue ice, very little worked by the water, a sign that it fractured at the last moment, just before the collapse of the great mass of ice ". There is no doubt that the cause was the unprecedented warming of the last few days, given that the ice melts above 0 ° C and in recent days the air temperature on the Marmolada has been very high: we are talking about 10 ° C at the top. “The freezing point (ie the altitude at which the air temperature is equal to 0 ° C) - continues the professor - was reached at over 4700 meters of altitude on Saturday. This means that in the Alps, and the Marmolada was no exception, everything melted if placed at altitudes below 4700 m asl. It is clear that at such temperatures the amount of water generated by the melting of snow and ice is enormous.

If this water is not quickly removed, if it does not flow away and remains trapped inside the glacier or in a crevasse, then events such as that of the Marmolada can happen ".

The state of the Italian glaciers : the most fragile in Europe Our glaciers are shrinking at the same speed as tropical glaciers: faster than those in Switzerland, Austria or Northern Europe. It depends on the fact that ours have dimensions and typological and geographical characteristics similar to the tropical ones. “Our glaciers - explains Diolaiuti - are more fragile than European ones due to various factors: geographic, we are exposed to the South, therefore with greater insolation and greater energy for melting; dimensional, in the Italian Alps the 903 glaciers present are 80% small, very small glaciers, therefore more vulnerable to melting due to high summer temperatures and with a disadvantageous surface / volume ratio which means that they can store little snow in winter ; superficial, that is the alpine glaciers are very affected by darkening, or darkening due to the deposition of black carbon and particulate matter, and therefore with a lower reflectivity to solar radiation and consequently a greater melting ".

The reduction of the Forni glacier between 2018 and 2022. Source: Greenpeace

Professor Diolaiuti was one of the curators of the new Glacier Cadastre, based on the revelation of very high resolution photos detected between 2005 and 2009, and developed by the University of Milan with the collaboration of all the Italian glaciated regions. "The New Cadastre describes the 903 glaciers present in the Italian mountains (902 in the Alps and 1 in the Apennines, the Calderone in the Gran Sasso)". It is the update of the 1959-1962 Glacier Cadastre carried out by the Italian Glaciological Committee in collaboration with the CNR: the comparison between the old and the new inventory tells us that all Italian glaciers have decreased by about 30% in just under 60 years . "Not only that: the comparison of the data of the Unimi cadastre with those of the European cadastre has shown that in the last 10 years the Italian glaciers have still lost area, 13%, and the total loss since 1959 to date amounts to 200km², an area comparable to that of Lake Maggiore ".

Italian glaciers could disappear: what the effects will be First of all, having 903 glaciers is not good news: their quantity is given by the fact that the heat reduces them into different pieces . So much so that only three glaciers have a surface greater than 10 km²: Adamello, Miage and Forni. Precisely in relation to the latter, the State of Milan has developed a continuous monitoring system that can be consulted online:

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The system monitoring of the Forni glacier. Source: University of Milan

A scientific article signed by Diolaiuti and other authors in the journal La Houille Blanche, makes the current screening of our white giants. The 903 Italian glaciers are all in the Alps, apart from two conformations in the Apennines. At a regional level, it is the Aosta Valley that hosts the most glaciers in Italy (132.90 km2), about 36% of the total. Lombardy (87.67 km2, 24% of the total) and Alto Adige (84.58 km2, 23% of the total) follow. But precisely for what was said at the beginning, it is the Lombardy region that hosts the largest number of glaciers (230) even though it is not the one with the greatest glacial extension in Italy: this is because 84% of the glacial bodies are smaller than half. square kilometer . According to the WWF, if temperatures continue to rise, between 2070 and 2100 the eternal ice from the Eastern Alps could completely disappear: the same fate that, although more difficult, could touch those of the Central Alps. Glaciers would remain only in the Western Alps, the highest ones. The problem of melting is progressive, also due to the fact that glaciers are becoming increasingly dark (the phenomenon of darkening, described above) and this makes them even more vulnerable to solar radiation. The famous magazine Science described in a recent study the prospect of increasingly green and therefore less and less white Alps: the bands most exposed to the increase in vegetation are those around 2300 meters above sea level, while those subject to snow loss they are around 3 thousand meters.

How are the Italian glaciers The disappearance of the glaciers will have different and certainly impactful effects: starting with the hydroelectric power plant that runs in the Alpine regions. “This phenomenon - continues the professor of the Statale - will have aesthetic and landscape impacts on our mountains (the Alps will be increasingly similar to the Apennines), impacts on tourism and attendance, impacts on biodiversity and geodiversity and ecological systems. Suffice it to say that my ecological colleagues have found bacteria capable of breaking down some pollutants on glaciers. Without ice these bacteria do not live and their virtuous role as bio-demolitioners will be lacking ".

How to react to the melting of glaciers Will the Himalayas be the only glacier to survive climate change? First of all, continuous monitoring to measure the danger of glacial risk phenomena as Diolaiuti explains: “It should be specified that by danger in geology we mean the possibility that a natural event occurs without evaluating the consequences for man and his works. Instead, we talk about risk when, in addition to the possibility of the event happening, the potential impacts on humans, infrastructures and settlements are considered and evaluated. It is therefore evident that if a collapse like that of the Marmolada occurred in a remote sector of Antarctica not frequented by scientists and mountaineers, without human presence, it would represent a very dangerous event but with zero risk. The event on the Marmolada for the place where it took place represented not only a highly dangerous event but also an accident of great risk due to the damage caused ".

Preserving glaciers by covering them with sheets does not seem to be a good solution A group of research centers and experts involved in the study of glaciers and climate change have signed a letter against this increasingly widespread practice, calling it a form of greenwashing It should be reiterated that the Marmolada did not present any dangerous profiles, but the high human turnout through tourist facilities and transport systems makes it a place to be monitored with specific attention. Often temporary, buffer solutions emerge to try to prevent the melting of glaciers. “Containment networks or structures that prevent the collapse of glacial portions are not possible, but it is possible to think of emptying glacial pockets or crevasses full of melt water with bypasses or of interdicting a glacial area subject to rapid evolution. But this can only be done after a serious monitoring program has been launched nationwide on the most frequented glaciers ". It is therefore clear that there is a need for up-to-date data and researchers capable of interpreting them. It is first necessary to intervene on the problem in a structural and overall way and only then to think about buffer solutions. It is no longer a question of preserving our historical landscape but our peaceful existence within the landscape that will become, through quick and intelligent decisions: this is the meaning of the term resilience.

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