As the Earth’s globally averaged surface temperature is increasing it is important to determine how physical and biological-human systems respond to and interact with climate. There is a lack of paleo-environmental information from remote sites such as high altitude glaciers (ice cores) that would allow linking the physical and the human systems.
Tyrol is a unique area in the Eastern European Alps with a very rich history. Its highest glacier, Vedretta Alta dell’Ortles (3905 m, South Tyrol, Italy) constitutes an important observational point to study how past changes in climate, ecosystems and human society influenced the atmosphere of the Alps. The potential of Mt. Ortles ice field has not been explored, mainly due to the difficult logistical access.
The opportunity to extract a new unique history, linking changes in climate and ecosystem conditions with past human activities, exists in South Tyrol in the Eastern European Alps from which no ice cores have been recovered. Indeed the only significant drilling sites in the Alps are located in the Western Alps (Col du Dom, Colle Gnifetti and Fiesherhorn) and recently have provided late Quaternary old ice (back to 10,000 years before present).
The glacier Vedretta Alta dell’Ortles covers the northwestern flank of Mt. Ortles (3905 m a.s.l., South Tyrol, Italy), the highest mountain in the Eastern Alps, from its gently sloped top part at 3870 m toward the lower ablation area at ∼3000 m. Mt. Ortles is located in the lowest precipitation area of the Alps and thus has the potential to contain older ice than what is normally observed in the Alps.
Nevertheless Vedretta Alta dell’Ortles may contain information over the last millennium with respect to
- climate (air temperature, amount of precipitation);
- ecosystems (composition of the vegetation, aridity conditions, types of exposed soils)
- human society (changes in land use/fire activities, emissions linked to mining/smelting and the industrialization).
Mt. Ortles is located just ~30 km from where the famous 5200 years old “Tyrolean Ice Man” (Oetzi) emerged from an ablating ice field. The excellent preservation of Oetzi suggests that the last few decades were the warmest on record over the last 5200 years in this region of the Alps. Indeed glaciers are rapidly shrinking in this area and therefore it is a high priority to retrieve this unique paleoenvironmental glacial archive from Mt. Ortles before it is lost.
By using high altitude helicopters, in 2009 and 2010 the first extensive investigations of the glacier Vedretta Alta dell’Ortles at 3850 m a.s.l was performed. It was found that the maximum thickness in the upper part of this glacier is ~75 m and lamination of the exposed ice layers is excellent down to bedrock. Firn and ice lenses were observed in a 10 m shallow core and the firn/ice transition was below ~24 m. The mass balance of the upper part of the Vedretta Alta dell’Ortles glacier was positive (~ 1000 mm y-1) during the last few years.
Most importantly, in spite of the current exceptionally warm summer temperatures and the occurrence of some meltwater percolation through the firn, the seasonal atmospheric signal was still recorded in the uppermost firn layers. This provides confidence that the ice formed before ~ AD 1980 (when summer air temperatures were much lower, ~2 ºC less than today in this area) recorded and still contains a paleo-environmental history. Clearly the continued warming trend predicted to occur over the next few decades, and the consequent increase in frequency and/or intensity of infiltration processes, will endanger the preservation of a glacial archive that is conserved in the deep ice layers of Mt. Ortles.
Further details can be found in the attached reports of activities performed in this framework during the years 2008, 2009, 2010, the 4 papers presented in international conferences and the 2 papers published in international peer reviewed journals (Scientific Reports section).
Operative and scientific objectives
The first goal of this operative program in 2011 has been to retrieve four ice cores from the upper part of the glacier Vedretta Alta dell’Ortles (3850 m a.s.l.) and secure them in the freezers at the Byrd Polar Research Center, in Columbus (USA). This mission is now ensuring the possibility of obtaining important environmental and climate information during the last few centuries or even back at the beginning of the last millennium.
These ice cores will advance the understanding of the significance of the recent and future changes in temperature, precipitation, vegetation, land use and anthropogenic emissions in this region of the Alps located in the rapidly warming area of the Mediterranean. The Mt. Ortles ice cores will fill an important gap in the spatial distribution of ice cores retrieved from the European Alps. Ultimately these records will offer a unique yardstick to be compared with other European records and those from low-latitude sites where records of climate, ecosystems, and human societies have been extracted.