First investigations of an ice core from Eisriesenwelt cave (Austria)

Autor(en)

Barbara May, Christoph Spötl, Dietmar Wagenbach, Yuri Dublyansky, Jakob Liebl

Abstrakt

Investigations into the genesis and dynamical properties of cave ice are essential for assessing the climate significance of these underground glaciers. We drilled an ice core through a 7.1 m-thick ice body filling a large cavern of the dynamic ice cave Eisenriesenwelt (Austria). In addition to visual core inspections, quasi-continuous measurements at 2 cm resolution comprised particulate matter, stable water isotope (delta(18)O, delta D) and electrolytic conductivity profiles supplemented by specifically selected samples analyzed for tritium and radiocarbon. We found that recent ablation led to an almost complete loss of bomb-derived tritium removing any ice accumulated since, at least, the early fifties leaving the actual ice surface even below the natural tritium level. The small particulate organic masses rendered radiocarbon dating inconclusive, though a crude estimate gave a basal ice age in the order of several thousand years. The visual stratigraphy and all investigated parameters showed a clear dichotomy between the upper 2m and the bottom 3m of the core, which points to a substantial change in the ice formation process. Main features of the core comprise the changing appearance and composition of distinct cryocalcite layers, extremely low total ion content and a surprisingly high variability of the isotope signature. Co-isotope evaluation (delta D versus delta(18)O) of the core in comparison with data from precipitation and karst spring water clearly indicate that ice formation is governed by (slow) freezing of dripping water.

Organisation(en)

Isotopenphysik

Externe Organisation(en)

Universität Heidelberg, Leopold-Franzens-Universität Innsbruck

Journal

Cryosphere

Band

5

Seiten

81-93

Anzahl der Seiten

13

ISSN

1994-0416

DOI

https://doi.org/10.5194/tc-5-81-2011

Publikationsdatum

2011

Peer-reviewed

Ja

ÖFOS 2012

105101 Allgemeine Geologie, 105904 Umweltforschung, 105102 Allgemeine Geophysik

Link zum Portal

https://ucris.univie.ac.at/portal/de/publications/first-investigations-of-an-ice-core-from-eisriesenwelt-cave-austria(12421ee9-f79b-44ba-8a04-8c968cb8ee5d).html