Chapter 30 - Ice Caves in Slovenia

Abstract

Slovenia is a middle latitude, Central European country. The ice caves were known and used traditionally as a source for water and ice. The first written reports and observations of cave ice are from the 17th century, and in the 19th century, many ice caves were studied by scientists. In the cave register of Slovenia, 551 ice caves are registered. The lowest is at an altitude of 645m. The majority of the ice caves are simple shafts with large entrances. Two important and well-known Slovenian ice caves are Paradana and Snežna jama na Raduhi. With an estimated ice volume of about 8.000m3 in the entrance, Paradana goes to a depth of about 100m, in which cold air currents freeze water as deep as 200m. Snežna jama na Raduhi has about 4000m3 of ice. In both caves, ice forms because of strong air circulation that cools the entrances of the caves in the cold half of the year. Air flow reverses in the warm half of the year and melts part of the ice. In present conditions, ice mass is decreasing in most of the known ice caves. Similar air circulation was observed also in numerous blowholes in the vicinity of Paradana ice cave, indicating existence of permafrost not only in caves but also in rubble at the bottom of dolines and filled cave entrances. The blowholes and cave entrances are the main reason for strong summer temperature and vegetation inversion in depressions in Dinaric karst.