Global warming as a result of climate change has been causing ice glaciers to melt for years, but the phenomenon can now also be measured in ice caves. This is confirmed by a new study from Austria.
The natural wonder of the ice cave
Thousands of ice caves lie hidden beneath the surface of our planet. Austria has the largest occurrence of the icy natural wonders. Researchers from the University of Innsbruck investigated for a Study eight such ice caves in the Alpine Republic. The leader of the team, Tanguy Racine, explains the research project aloud Wissenschaft.de: “There are already studies on individual ice caves. However, we now wanted to create a comparative analysis for the first time and have therefore focused on the development of several caves that are in comparable settings: similar altitudes and a steeply to vertically sloping geometry.”
The researchers focused their investigations on shaft-shaped ice caves. Like glaciers, these form from precipitation. Snow slides into the cave in winter and hardens there, gradually creating huge layers of ice.
The dating of the ice sheets
At the beginning of the investigations, it was necessary to date the ice layers in order to later calculate how much ice was in the cave at what point in time. For this, the team used the so-called radiocarbon method. They used it to determine the age of pieces of wood found in the layers of ice.
Racine explains: “We focused on the smallest inclusions of wood in the ice layers. Because the age of these remains of wood, which fell into the caves from the outside, can be precisely determined”. The researchers were thus able to determine data from a period of up to 2000 years in the past. Thanks to this dating, the scientists were able to compare a total of 107 samples and draw up a balance.
The team was able to check their results using existing analyses. It is known that between 850 and 1200 AD there was a warm climate anomaly. This might also be demonstrated in the team’s dated ice inclusions. For the period of the Little Ice Age, which ran from 1400 to 1850, the researchers were able to see a positive development in the ice.
Dramatic developments in the last decades
The results of the investigations show that there have already been dry periods with little precipitation and a low ice balance in the last 2000 years. However, such a negative development as in the last 20 years is unique. “We’re seeing a rate of ice retreat that hasn’t been seen in any period in our measurement period over the past 2,000 years,” Racine said. “It is not only glaciers that show an above-average negative mass balance, especially in the last few decades. The ice in the ice caves is also severely affected by the consequences of the rise in temperature and the fall in rainfall”.
