IVACICEVA CAVE: AN ICE CAVE IN THE SE ALPS

Cave ice and mountain glaciers contain a wealth of paleoclimate and geochemical information, information being lost with the melting of the temperate zone cryosphere. The Triassic-Jurassic shallow water carbonate Julian Alps of northwestern Slovenia are home to the Triglav Glacier and Ivačičeva Cave, an ice cave. Historical ice mass loss from Triglav Glacier has been observed since the late 19th century and documented since 1946 by the ZRC SAZU Anton Melik Geographic Institute. Glacial ice loss has exposed caves and shafts containing ice. Ivačičeva Cave, near the Triglav Glacier, is one of the more than 500 ice- and snow-containing caves registered in Slovenia.

Within Ivačičeva Cave (2471 m a.s.l.; 219 m long and 33 m deep), a 2-meter vertical profile of ice was sampled every 5 cm from an ice face). The cave was sampled in early September 2019, approximately at the end of the melting season. The samples were analyzed for major ions, nutrients, and stable isotopes of water. Major ion data show Ca>>Mg=Na>K and HCO₃>>Cl=SO₄>F. The calcium to bicarbonate molar ratios suggest that limestone dissolution is the major source of solutes to the cave ice. Constancy of both 𝛅¹⁸O and 𝛅D values and their locations plotting near the local meteoric water line suggest that present day local precipitation is the source of water for the ice. Ice formed from annual melting and refreezing of ice is also possible. Further analysis of data should clarify whether there is reliable paleoclimatic information recorded in the cave ice and what processes, including thaw-freeze, seasonal input, or hydrologic variations, control the geochemical signature.