Ice is melting on Velebit. It has been there for several thousand years.

In the Northern Velebit National Park, which is also among the coldest locations in Croatia this summer, a two-week speleological expedition is coming to an end, during which 33 caves were explored and documented, and microclimatic conditions and the level of permanent ice, which has been observed to be decreasing, were monitored.

According to previous research, the age of permanent ice is estimated to be between 400 and 3,000 years.

Data collected during the expedition show that winters in Northern Velebit are still extremely cold, and the lowest temperature last year was around minus 22 degrees Celsius at one of the locations, reported the Speleology Department of the PDS Velebit and the Speleology Commission of the Croatian Mountaineering Association.

They emphasized that Northern Velebit is among the coldest locations in Croatia this summer as well

Although low winter temperatures favor the preservation of cold microclimatic conditions underground, changes in the amount and level of permanent ice have been recorded in some of the pits, they warned.

They also said that the cold air, which flows from some pits even during the summer, has allowed snow to remain in some locations in Hajdučki kukovi even in August, “which shows how special the microclimatic conditions of Northern Velebit are”.

However, they added, this does not mean that the underground is not exposed to the influence of climate change. “In some caves, we are recording a significant decrease in the level of permanent ice, and in some places its complete disappearance,” said Dalibor Paar from the Faculty of Science and Mathematics in Zagreb.

Expedition co-leader Ema Buljan said that they explored 33 speleological objects with a total depth of about 1,100 meters and supplemented the data on larger explored caves. 51 speleologists from ten speleological associations from Croatia, Austria, the USA, Portugal and Bosnia and Herzegovina participated.

During the expedition, changes in microclimatic conditions in the caves and the connection of the deep underground with surface ecosystems were also investigated.

The expedition was led by Ema Buljan and Olga Jerkovi&cácute; Peri&cácute; from the Speleology Department of the PDS Velebit and the Speleology Commission of the Croatian National Park, with the support of the Northern Velebit National Park.

The organizers state that the collected data will contribute to a better understanding of the impact of climate change on the underground and aboveground ecosystems of the national park and can be used in the preparation of educational content about the natural values ​​of Croatia.