The Brenta Glaciers
In the area there are some glaciers of modest dimensions that cover a total surface area of 204.47 hectares: Lower Vallesinella Glacier, Upper Vallesinella Glacier, Tuckett Glacier, Upper Tuckett Glacier, Upper Brenta Glacier, Brentei Glacier, Northern Sfulmini Glacier, Bocca di Brenta Glacier, Crozzon Glacier, Camosci Glacier, Agola Glacier, Prà
Fiorì Glacier, XII Apostoles Glacier, Sacco Glacier, Ambiez Glacier. The Lower Vallesinella Glacier is situated in a deep, narrow valley and, as with many glaciers in Brenta, is enclosed between steep rocky walls characterized by peaks that reach almost 3000 m (Campanile di Vallesinella and Cima Falkner). It is fed by both direct snowfall and avalanches. Its current surface area is less than 10 hectares. The Italian Glacier Register (1962) considered it joined to the Upper Vallesinella Glacier (649.1), attributing to it a total surface area of 38 hectares. The front retreated by around 35 m between 1995 and 1998 and the surface area is almost completely covered with detritus. The Upper Vallesinella Glacier was considered separate from the Lower Glacier already in the Italian Glacier Register (1962). It is set in the northern slopes of Cima Sella. The last surveys, relating to the ‘90s, attributed a surface area of less than 2 hectares, and from the end of the ‘90s the glacier was considered extinct. The Tuckett Glacier is situated in the deep narrow valley that culminates in the Bocca di Tuckett and has recently undergone considerable morphological transformations, subdividing into different parts and losing entire portions. In 1995 there was the spectacular detachment of a section of the glacier that then melted, causing a retreat of the upper front of 100 m in one year. Until the end of the 1800s it was one of the main glaciers in the Brenta Group and had a surface area of around 66 hectares, reducing to around 50 hectares as reported in the Italian Glacier Register in 1962. Today the surface area is less than 15 hectares. A few years ago it was completely cut off from its connection with the Cima Brenta hanging glacier. It is fed mainly by avalanches that fall from the rocky walls that surround it, but, given its relatively low altitude, in the last few years the residual snow has melted completely and so cut off its supply. Recently, a considerable increase in detritus has been observed, especially in the lower part. With the current climatic tendencies, the Tuckett Glacier is destined to undergo further transformations along with almost all the glaciers in the Brenta Group. Below the glacier interesting glacial morphologies may be observed, such as the sharp, right lateral moraine from the Small Ice Age (1550-1850) that in part is crossed to reach the Bocca di Tuckett. The Upper Tuckett Glacier recently broke away from the Tuckett Glacier (650.0) and is now considered a distinct entity. The spectacular hanging ice cap is situated on the north-west slope of Cima Brenta. The surface area is around 5 hectares and is fed directly by snowfall. The Upper Brenta Glacier is located in a narrow valley cut in the north-west side of the Cima Brenta massif. It is a small glacier which, along with all the other Brenta glaciers, has suffered a great reduction in surface area and thickness over recent years. The Italian Glacier Register (1962) attributed a surface area of 15 hectares, while, according to surveys carried out in the early ‘90s, it has reduced to around 4.5 hectares. The Brentei Glacier is in a narrow valley situated to the south of the Cima Brenta massif. It has by now reduced to next to nothing and is almost completely covered with detritus. The glacier is supplied by snowfall but also by avalanches that discharge from the side of the mountain. The Italian Glacier Register (1962) attributed a surface area of 10 hectares, which reduced to 4.5 by the mid-‘90s. The Southern Sfulmini Glacier occupies a large cirque dominated by Cima d’Armi and by Torre di Brenta, in one of the most enchanting and spectacular areas in the Brenta Group. In the mid-‘90s the front reached an altitude of 2620 m,, while the surface area in the same period was 9.5 hectares. The Italian Glacier Register (1962) reported a surface area of 18 hectares, but at the time the glacier was still joined to n° 653.1. The lower part is abundantly covered with detritus. It is fed by snowfall and by avalanches that fall on the section that covers the side of the Torre di Brenta massif. The front retreated by around 25 m between 1990 and 1996. The Bocca di Brenta glacier has by now reduced to next to nothing and is preserved only thanks to its favourable exposure and topographical location, with walls that surround it on three sides. It is located in the narrow valley that leads to the Bocca di Brenta and already at the beginning of the ‘90s was subdivided into three distinct bodies by a series of rocky cornices. At the end of the summer, the basin which contains the remains of the glacier is often full of residual snow that accumulated during the winter avalanches. The total surface area of the three portions was around 3 hectares at the beginning of the ‘90s, while the Italian Glacier Register (1962) attributed a surface area of 4 hectares. The Crozzon Glacier is distinctly subdivided into two areas, a level area that occupies the top of Cima Tosa (3170 m) and a steep section wedged in the canyon between Cima Tosa and Crozzon di Brenta. At the bottom of the canyon the glacier fans out, resting on a large rocky cornice. In this area the glacier reaches an altitude of around 2300 m, among the lowest in the Brenta Group. The part at the summit is fed mainly by direct snowfall, while the canyon is fed mainly by avalanches. The ice cap at the summit has reduced a lot over recent years, while the canyon has not undergone any major modifications, excluding a general “thinning”. The Camosci Glacier is situated in a valley cut between the Cima Tosa massif – Crozzon di Brenta and the Cima di Val Stretta. The lower part is abundantly covered by talus, while a rocky outcrop roughly halfway up the glacier is separating it into two distinct parts. It is fed both by direct snowfall and accumulations after avalanches that are discharged from the surrounding rocky walls. The Italian Glacier Register attributed a surface area of 27 hectares, reduced to around 23.5 at the beginning of the ‘90s, after which the front retreated by around 80 m. The Agola Glacier is the most extensive in Brenta and may be considered representative of all the glaciers of the mountain group. As with many other glaciers in the group, in fact, it is found at a relatively low altitude (from 2600 to 2900 m) and is preserved thanks to the protection offered by the steep rocky walls that surround it (an arcing rocky ridge that culminates with Cima d’Agola and Cima d’Ambiez). It is characterized by a triangular form with a well defined toe area that does not have any significant covering of detritus. There are some transversal crevasses in this area. The glacier is fed by various means but of particular importance are the avalanches that fall on the upper part of the glacier where the last margins of the residual winter snow are preserved. Until a few decades ago it was connected to the nearby Camosci Glacier by the saddle of the same name, which today can easily be crossed without treading on snow. The Italian Glacier Register (1962) noted in this area a retreat of 13 m from 1911 to 1950 and a further 27 m from 1950 to 1958. The surface area has also suffered a drastic reduction, from 44 hectares at the end of the 1800s, to 34 hectares in 1962 (The Italian Glacier Register), to 25 in 1991 to its current 23 hectares (data from 1997). In the surrounding area there are interesting dolomitic glacial morphologies, such as roche moutonnée arranged in steps (rocky outcrops smoothed and polished by the passage of the glacier) and the imposing and sharp left lateral moraine dating back to the Small Ice Age (1550- 1850), certainly one of the biggest in the Brenta Group. The Prà Fiorì Glacier is situated in a ba sin delimited by a crest line that culminates at Cima Prato Fiorito. It may be considered as a typical cirque glacier, even though the basin it is located in, is rather wide and open. Due to its characteristics, this glacier was considered representative of all the Brenta Group and, from the 1990s the Trentino Glaciological Committee have followed its evolution carefully and accurately, carrying out precise topographical surveys of its surface every year. The surface area of the glacier was calculated by Richter (1888) as 39.6 hectares and reduced to around 27 in the 1960s (Italian Glacier Register, 1962). According to the last surveys the surface area has gone from 11 hectares in 1990 to 8.3 in 1999 with a reduction of around 80% in 110 years. Over the last few years it has suffered a dramatic reduction in thickness, confirmed by the emergence of a rocky step a little way above the toe area, a step that has broken the body of the glacier into two parts. The lowering of the surface, measured with topographical surveys was around 8-10 m between 1990 and 1995. The 12 Apostles Glacier occupies a large cirque situated at the top of the Val di Sacco and is delimited by the Croz di Selvata peak, Padaiola and Padaiola Bassa. It has greatly reduced in surface area and currently is made up of a layer of sub-rectangular ice resting on the rocky walls behind. It is fed by direct snowfall but the avalanche accumulations also play an important role. The Sacco Glacier is almost entirely covered by a thick blanket of detritus which makes it difficult to detect. It is the remainder of a glacier that is preserved thanks to the favourable exposure and the covering of detritus. It is on the bottom of a narrow cirque cut into the south-west slope of Cima di Vallon. The Italian Glacier Register (1962) reported data that referred to 1911 and attributed a surface area of only 5.5 hectares. At the beginning of the ‘90s the remaining surface area and detritus cover was estimated at just less than 3 hectares. The Ambiez Glacier is situated at the head of its homonymous valley, in a narrow valley cut into the southern slope of Cima Tosa. It is one of the few south facing glaciers of the Brenta Group, an unfavourable exposure with regard to its preservation. It is mostly covered with detritus and in the lower part there are also large masses due to the collapse of Torre Jandl in 1957. The Italian Glacier Register reported a surface area of 12 hectares, while the calculations for the beginning of the ‘90s attributed an area of around 10 hectares. It is fed both by direct snowfall and avalanche accumulations, with a series of well visible residual snow fans on the upper part of the glacier at the end of summer. There are imposing moraines from the Small Ice Age (1550-1850) visible just above the Agostini Refuge.