Edited by our Austrian correspondent, Gerhard Hohenwarter
The Eiskar glacier is the only still existing glacier in the Carnic Alps just a few meters north of the Italian-Austrian border, and therefore the southernmost glacier in Austria. This small ice body is located at about 300-400 m from the peak of Kelllrspitzen-Creta delle Chianevate (2769 m) in the Kellerwand massif at the base of the north cliffs at about 2200 m.
The shady location, a lot of fresh snow in winter as well as large avalanches that run down from the surrounding walls onto the glacier mean that this glacier still exists despite its low altitude.
Due to its characteristics in terms of altitude and snow accumulation, this glacier is very similar to the small ice bodies of the Julian Alps.
The Eiskar glacier below the peak of Creta delle Chianevate-Kellerspitzen. Photo Gerhard Hohenwarter
The glacier was first surveyed in 1897 by the Italian geographer Olinto Marinelli. Up until 1992, follow-up measurements were made in the Eiskar at irregular intervals. Since the beginning of the 1990s, however, Austria's southernmost glacier has been part of the official measuring program of the Austrian Alpine Association. Thus, annual follow-up measurements have been taking place on the Eiskar glacier for 30 years now.
Change in length [m] of the Eiskar glacier 1897 - 2021 at the benchmark MO I/ H16
The 1990s in the Southern Alps were repeatedly marked by winters with relatively little snow, which caused the glacier to retreat rapidly during this period. From the turn of the millennium, on the other hand, there were some winters with extremely high snowfall. Especially in the period between 2008 and 2014, the glacier was even able to regain mass over several years.
Due to global warming, however, the melting season is becoming noticeably longer and the glacier partly started to retreat again.
Change in length [m] at Eiskar glacier, single years and total
Nevertheless, after exceptionally snowy winters, the Eiskar glacier still has a positive mass balance. After the glacier budget year 2019-20 brought no significant change in length and a slightly positive mass balance, an extremely snowy winter followed. In December 2020, around 200mm of precipitation fell within 24 hours in the form of snow. This was the heaviest December precipitation recorded in Austria! Within one week, more than 500 mm w.e. of precipitation accumulated.
The consequence of the heavy snowfall was not only large snow accumulation but also huge avalanches on the glacier. For the entire winter, a precipitation sum of 1200 mm w.e can be estimated on the basis of the surrounding weather stations.
Il The small Eiskar glacier abundantly covered by debris in several sectors, with the huge frontal moraine half September 2021.
The cold spring also had a positive effect on the glacier. From the beginning of April, temperatures were almost continuously below average. In May there were a total of 12 days with snowfall at the Eiskar. As a result, the accumulation period on Austria's southernmost glacier did not end until 27 May.
The transition from late-winter May to high-summer June took place just within a few days. With a positive deviation of 3K°C, June 2021 was one of the warmest on record. The snowmelt was correspondingly strong this month. The strong snowmelt also continued in July.
In August, a blast of cold air shortly after the middle of the month caused significantly cooler temperatures. However, the melting season on the Eiskar glacier only finally ended with the first snowfalls in early October.
Gerhard Hohenwarter surveying in the snow pit
At the beginning of the melting season in early June, in some places in the Eiskar there was up to 20m of snow! Over the entire summer, 6 to 9 m of snow melted. When the glacier was measured in mid of September, 72% of the glacier was still covered with snow from last winter. The greatest snow depth was just over 10m. The remaining 28% of the glacier was covered with debris.
Due to the excellent snow cover, the ice edge could not be determined at any of the eight measurement marks. At around 2250 m, a 2.4 m deep snow shaft was dug and the snow density was measured. The mean snow density was 620 kg/m³. Of the four ablation levels distributed across the glacier, only one was free of snow. The sinkage of the ice surface there was 0.1 m in a year-on-year comparison.
The evaluation of the snow depth measurements combined with the snow density measurement and the ablation value of the ice level results in a mass balance of +1650mm water equivalent for the Eisar glacier. This makes the glacier balance year 2020/21 one of the most positive in the last 30 years. Similarly large or even larger mass gains only occurred in 2000-01, 2003-04, 2008-09, and 2013-14 when 2700 mm w.e. were recorded and represent the highest accumulation of the last 30 years.
Hohenwarter in the Randkluft of Esikar
The cirque glacier has not lost any significant mass or area in its western section in the last 15 years. Here, in snowy periods, large avalanches also cause meter-high snow deposits on the glacier, which do not melt completely in summer. On the eastern part of the glacier, on the other hand, no major avalanches occur. For this reason, the glacier in this area has lost considerable mass and extent in recent years.
Since 2008, the glacier in the eastern section has lost around 7.5m in ice thickness. In the western part of the glacier, however, the current snow and firn extent corresponds roughly to the glacier margin of 2005. It is therefore evident that exceptionally snowy winters in connection with large avalanches can enable the survival of this glacier, which is currently around 16 ha in size, for several years to come.
The results of the measurements at the Eiskar correspond to the observations of the small glaciers and ice patches in the Italian part of the Julian Alps.