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Snowfields of the Majella and the Appennine panorama, by Cristiano Iurisci

majella 's photos

This article was published in the magazine D’Abruzzo in 2004. Here we have the complete version that was given to us by Cristiano Iurisci.

After the “very hot” Summer of 2003, words like greenhouse effect, ozone hole, regression of glaciers and global warming have become very common. These words, that have a very strong scientific and not completely definite meaning, have been often used and misused by the mass-media, so that, after every environmental disaster, they become the only causes and the only culprit. The discussion is in a matter of fact much more ample and complicated.

Much has been written and said, in this regard, about “our” Calderone, that is the only glacier we have in the Appennine range, situated among the highest peaks of the Gran Sasso. For some it is considered extinct, for others in “coma”, and for someone else, it isn’t as serious as it seems because it is simply half-buried by its own debris. As we can easily guess, its “survival” is directly proportional to climate and so to the climate of “our” Abruzzo.

Infact, ice melts at a fixed temperature set by the laws of physics, which is zero degrees centigrate; so little variations above this temperature induce its melting, otherwise its conservation. The constant reduction and thinning of the Glacier of the Calderone during the last 25 years is known by all those, scientists and not, who walk next to it when going towards the peak of the Corno Grande. The older excursionists remember that in the past a tract of snow had to be crossed even at the end of August to reach the summit, and now instead, already at the middle of July it is already a stony ground. This can be a simple and intuitive method to verify, even in a simplified way and on a local scale, the thesis of global warming or climate change. Trying not to make the most common mistakes such as wanting at any cost to be sensational or catastrophic, what is really the truth? According to the official data, there is warming and it is marked enough in “our” Abruzzo. As we can see in the table below, the average temperature has gone up about 0.8 degrees in the last one hundred years (data coming just from Lanciano).

What will happen in the future is still unknown to us, and even if it is almost certain that we will be going towards a further warming, the autoregulating mechanisms of weather are not at all clear and scientifically demonstrated.

We will not go into the subject climate both for my incompetence and for the difficulty of such a subject, but let’s elaborate more thoroughly the “effects” that it induces in glaciers and snowfields. Climate influences directly glaciers both in the accumulation (snow precipitations) and in the ablation (melting of snow), but the “response” of the glacier to a period unfavorable or favorable to glacialism is strictly subordinated to its extension and location.

A small glacier (0,5/2,5 km2) will almost immediately show the consequences of such variations, on the contrary, to notice them on a medium-large one (10-1000 km2), you must wait from several years to a few decades. Not considering the importance of its location (latitude), you can understand perfectly that to study glaciers like the Calderone or “snow glaciers” (subject of this article) of the Majella permit us to have results that are immediately verified.

The fact is that it helps us understand if one year was more or less warm, if it was more or less rainy increasing the interest in their study and their observation during the years.

Besides the Calderone there are at least four perennial snowfields on the Gran Sasso and the same number (or more) on the Majella.On the second, the highest concentration of snowfields is located between Mt. Acquaviva (2737 m) and the Peak of the Murelle (2596 m). In Val Forcone we can find at least four, of which the largest, called by the locals the “glacier”, is located on the first slope of Val Forcone, at almost 2200 m. Because of its extension which measures from 90 to 110 m. in lenght and 20/25 m. in width (measurements taken at the end of the season, usually after the 10th of September) it can be classified as a snow-glacier. In the same valley, a little further down, between 2050 and 1950 m. you can generally find another two small snowfields, usually 30/50 m. in lengtht and 10/15 m. in width; further down in the valley, where it tightens like a canyon, there are more snowy heaps, which vary every year, mostly from 1920 to 1850 m. situated in a suggestive landscape almost like the moon. This place never stops surprising everyone for its particular climate, infact in one of the tight and steep canals that cross the rocky wall of Mt. Acquaviva and that precipitate directly in Val Forcone, we can find other tight and long “hanging” snowfields. Up to a few decades ago, some of these snowfields were connected directly with some of the ones in the valley, forming snowfields with the characteristic shape of a “Y”. In the last years (especially after 1990), the unfavorable conditions have caused its withdrawal and so its “rupture” from the ones in the valley; and infact today we find them at 100/150 m. higher, while the ones that filled the tighter and thinner canals, have completely disappeared. These snowfields which are located between 2250 m. and 2500 m. have a length that goes from 50/100 m. (the biggest one is almost 200 m.!) but their width is just 15/20 m.!

After the very warm summers of 1994 and 1998, some of these have suffered ruptures from the inside as to appear sometimes as many small snow/ice plaques separated at parts by steep gravel, not hiding though its original shape. On the northern side of the Peak of the Murelle we can find some small perennial snow plaques; here we can’t really speak of snowfields, both for their small dimensions and for their extreme variability each year, so that some disappear during winters that are particularly low in snowfalls or very hot summers. An exception can be made by the one located in the Valle dell’Inferno, that for its length and width can be considered a snow-glacier. Located in this tight valley at an altitude of 1150/1200 m., its dimensions are length 150 m. and width 30/35 m. It is usually covered by every kind of debris, but we don’t have photos and “official” details, for its position, very hard to reach. Always on the northern side of the Peak of the Murelle, in the spectacular valley of Selvaromana, we can find other snowfields similar to these. Some are situated at the foot of the large north wall of the Murelle, at an altitude of about 1600 m. Their small dimensions (they don’t exceed 20/30 m. on each side) compromise their “presence” at the end of the season so that, in October 2002, one of them had disappeard and the other was reduced to a heap of ice of a few square meters, but in October 2003, both of them reappeared in their normal size. Further up we find the snowfield of the valley of Selvaromana, located at almost 1400 m., next to a small canyon that derives from a crag of the Fusco shelter. This one, too, undergoes enormous variations because of the type of its feeding, but, on average, it measures 35/50 m. in length and 15/20 m. in width. If we change location we move towards the Valle of Orfento where we find a small snowfield positioned in the “mucchia of Caramanico” at an altitude of almost 1550 m. Its dimensions, very small in these last years, go from 40/60 m. in length and 20 in width. In the same valley, but further up, in the basin that separates Mt. Rotondo from Mt. Focalone, we find another snowfield, even if it is not always there every year. This one occupies the bottom of the basin, and in particular years, it can exceed 200 m. on each side, but, since it is not very protected by close rocky walls, it disappears completely after particularly unfavorable periods. I will stop here in my list of snowfields because the other snowy spots, even if they are numerous in our Majella massif, are of very small dimensions and not present every year, and so scarcely important.

What distinguishes a snowfield from a snow glacier? The former is just an expanse of snow, more or less wide, that “resists” at least for one season. Instead a snowy glacier is a snowfield which is larger that resists for a few consecutive years and that is thicker, almost like a glacier, generally around 800 gr/dm3. Practically a snowy glacier is almost a glacier only that it doesn’t have some of its typical morphological characteristics, like superficial fractures and the sliding towards the valley.

From our school books we remember that the limit of perennial snow at our latitudes is 3000 m., so how is it possible that we have so many snowfields in our mountains? If we look at the graphic below we can understand that there are two important factors to set the parameters for the limit of snow: annual precipitations and summer temperatures. For the Majella massif, the extimated precipitations on Mt. Amaro (the peak) are about 2200 mm per year, while the temperatures during the month of July brought down to sea level are 25.3°C. With these parameters the limit should be around 3090 m., and only in particularly rainy and, at the same time, cold years the limit would go down to 2800 m. The years that are favorable to the formation and conservation of snowfields would be rare; the answer to our question comes from the type of “feeding” that these snowy surfaces have. Besides the normal snow precipitations from the sky, we must add those brought by wind or avalaches; in these cases the annual precipitations, even if only locally, may double if transported by wind or get up to four times if by avalanches. If we consider that all the snowfields on the Majella are located between 1200 m. and 2500 m., and so widely below the limit of perennial snow, it would be very difficult for them to become glaciers! If we just move a few meters from these local and small surfaces it would be “impossible”. Of the three types of snow accumulation, snow transported by wind is the most predominant in Val Forcone, while the one brought by avalanches is predominant in the valleys of Selvaromana, of Inferno and of Orfento; scarce and slightly significant are those formed by both (wind and avalanches). One of the most important factors in the “conservation”of snow is its specific weight. Usually the more this value is close to the one of ice in a glacier (more than 850 gr/dm3), the more its melting will be slow, since it is not very permeable to the rays of the sun, to rain and wind.

The sequence of the “tranformation” of the snow from fresh snow to old snow, in “firn” (snow for a snowfield), and at the end in ice, can be more or less long, and it can last from a few months to many years. We can deduce that if the transformation happens faster, it will be easier for the snow to “survive” in the hot summer days. For the snowfields which derive from the wind the process can be slower than for the ones created by avalaches. Infact, often, big accumulations of snow brought by the wind up in the mountains can literally disappear just with a month of summer heat if the snow hasn’t been “correctly” transformed.

This probably depends on the limited number of freezing/melting cycles (that help to eliminate the air bubbles that are in the snow) that take place in the high altitudes of the Appennines where in a few days you can pass from winter to summer with melting occuring even during the night hours. Instead, in the snow from avalanches, it is the strong impact on the ground that already creates part of the transformation, eliminating part of the interstitial “air” in-between the snow flakes. To this we can add the continuous freezing/melting cycles possible in winter too for the medium-low altitudes, which permit to reach a density typical of the firn even before summer, that is when the melting becomes daily and continuous. With these studies it is possible to explain how, notwithstanding all the snow that fell in 2003, the snowfields high up in the mountains (created by winds) “suffered” very much the long hot summer, which brought about a strong regression; instead, the ones created by avalanches resulted stationary or even bigger.

Cristiano Iurisci

Average temperatures from 1903 to 1941

grafico 1.JPG

Average annual temperatures from 1903 to 2003


Average annual precipitations


Local weather data and high altitude temperatures