Alpine ice caves on brink of shrinking, study shows climate change to blame

According to studies, alpine ice caves in Austria are shrinking due to climate change. Only a small number of the thousands of known ice caves around the world have been thoroughly researched, with Austria having one of the highest densities.

Eight descending ice caves in Styria, Tyrol, Upper Austria and Carinthia have been extensively examined in recent years by a team of researchers and scientists from the universities of Belfast and Innsbruck using a comparative research methodology.

(Photo: Photo: Tigerente / Wikimedia Commons)

According to Tanguy Racine, the unique ice caves have already been the subject of solid studies. The research, which focused on the development of ice in several caves that are all in comparable environments – similar elevation as well as steep to vertically inclined geometry – was the first time a comparative analysis was carried out. .

Racine is part of the Quaternary Research Group of the Department of Geology. He treated the subject in detail in his thesis. The ice formations in these caves are the result of solid precipitation, especially snow, which slides into the cave during the winter and freezes there when the temperature drops.

Charlotte Honiat and Tanguy Racine from the Department of Geology collect ice samples from the Tyrolean Guffert Eisschacht for laboratory analysis.

Ice cave development

The team used the radiocarbon method to measure the age of the ice sheets in the caves, which were often several meters thick. Racine explains the procedure, saying the research team focused on the smallest inclusions of wood samples in the ice layers to date the ice. It is possible to determine the exact age of these wooden fragments that fell from the outside into the ice caves.

The extensive database, which includes 107 dates of wood-in-ice samples, provides an accurate picture of ice accumulation and deposition in ice caves from some time up to 2,000 years ago.

Using this strategy, the team was able to demonstrate the theory that historically recorded glacial advances, such as those that occurred during the “Little Ice Age”, are also reflected in the growth of ice mass in caves. of ice and occur at the same time.

The geologist goes on to say that similar ups and downs in ice development can be seen in glaciers and ice caves over the past two thousand years. The amount of snowfall in winter and the heat in summer are crucial factors for both. The findings also demonstrate that a significant portion of Austria’s underground ice dates back to the “Little Ice Age”, which occurred between the 15th and 19th centuries.

Also read: Alpine glacier collapse kills six in Italy; Snowpack and icy rock hit hikers

Shrinking Ice Caves

Racine notes that glaciers aren’t the only ones that have recently shown an above-average negative mass balance. The balance of the ice caves is also negative. The effects of rising temperatures as well as decreasing rainfall have also had a significant impact on the ice caves.

The study demonstrates a rate of ice retreat that has never been recorded during our 2000 year measurement period. Several cases come to mind: for example, monitoring in the Guffert Eisschacht in Steinberg am Rofan revealed a decrease in the snow surface of almost three meters between 2019 and 2021, and Eisgruben Eishöhle in Sarstein, Upper Austria, has lost 10 meters of ice thickness in the last 40 years. The Upper Austrian Kraterschacht in the Sengsen Mountains lost 20 meters of ice during this time.

Similar to glaciers, this development can be attributed to human-induced climate change. Racine clarifies that it should be assumed, especially for small and medium-sized ice caves, that they will significantly lose ice mass or even become completely ice-free in the coming years. The clock ticks noisily.

It must be assumed, especially for small and medium-sized ice caves, that they will lose considerably more ice mass or even become completely ice-free in the coming years. The clock ticks noisily.

In order to preserve science-relevant climate data in the long term, researchers in Innsbruck will carefully remove ice cores from alpine ice caves in the coming years and keep them cool, reports Science Daily.

Related article: Rapidly melting alpine permafrost may cause global warming

© 2022 All rights reserved. Do not reproduce without permission.

Teresa H. Sadler