Journal cover Journal topic
The Cryosphere An interactive open-access journal of the European Geosciences Union
The Cryosphere, 12, 401-412, 2018
https://doi.org/10.5194/tc-12-401-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
31 Jan 2018
Investigating cold based summit glaciers through direct access to the glacier base: a case study constraining the maximum age of Chli Titlis glacier, Switzerland
Pascal Bohleber1,2, Helene Hoffmann2, Johanna Kerch2,3, Leo Sold4,a, and Andrea Fischer1 1Institute for Interdisciplinary Mountain Research, Austrian Academy of Sciences, Innsbruck, Austria
2Institute of Environmental Physics, Heidelberg University, Heidelberg, Germany
3Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany
4independent researcher
aformerly at: Department of Geosciences, University of Fribourg, Fribourg, Switzerland
Abstract. Cold glaciers at the highest locations of the European Alps have been investigated by drilling ice cores to retrieve their stratigraphic climate records. Findings like the Oetztal ice man have demonstrated that small ice bodies at summit locations of comparatively lower altitudes may also contain old ice if locally frozen to the underlying bedrock. In this case, constraining the maximum age of their lowermost ice part may help to identify past periods with minimum ice extent in the Alps. However, with recent warming and consequent glacier mass loss, these sites may not preserve their unique climate information for much longer. Here we utilized an existing ice cave at Chli Titlis (3030 m), central Switzerland, to perform a case study for investigating the maximum age of cold-based summit glaciers in the Alps. The cave offers direct access to the glacier stratigraphy without the logistical effort required in ice core drilling. In addition, a pioneering exploration had already demonstrated stagnant cold ice conditions at Chli Titlis, albeit more than 25 years ago. Our englacial temperature measurements and the analysis of the isotopic and physical properties of ice blocks sampled at three locations within the ice cave show that cold ice still exists fairly unchanged today. State-of-the-art micro-radiocarbon analysis constrains the maximum age of the ice at Chli Titlis to about 5000 years before present. By this means, the approach presented here will contribute to a future systematic investigation of cold-based summit glaciers, also in the Eastern Alps.

Citation: Bohleber, P., Hoffmann, H., Kerch, J., Sold, L., and Fischer, A.: Investigating cold based summit glaciers through direct access to the glacier base: a case study constraining the maximum age of Chli Titlis glacier, Switzerland, The Cryosphere, 12, 401-412, https://doi.org/10.5194/tc-12-401-2018, 2018.
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In this study we use an existing ice cave at Chli Titlis (3030 m, central Switzerland) to obtain direct access to ice at the glacier base. Using standard glaciological tools as well as the analysis of the isotopic and physical properties we demonstrate that stagnant cold ice conditions still exist fairly unchanged more than 25 years after a pioneering exploration. Our radiocarbon dating of the basal ice indicates that Chli Titlis has likely been ice-covered for about the last 5000 years.
In this study we use an existing ice cave at Chli Titlis (3030 m, central Switzerland) to obtain...
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