High-alpine Glacier Record Influenced by Melting
- 1Laboratory of Environmental Chemistry, Paul Scherrer Institute, Villigen PSI, Switzerland (carla.huber@psi.ch)
- 2Department of Chemistry and Biochemistry, University of Berne, Berne, Switzerland
- 3Oeschger Centre for Climate Change Research, University of Berne, Berne, Switzerland
- 4Department of Geosciences, University of Fribourg, Fribourg, Switzerland
- 5Institute for the Dynamics of the Environmental Processes, National Research Council, Venice, Italy
- 6Deparment of Environmental Sciences, Informatics and Statistics, Ca’ Foscari University of Venice, Venice, Italy
High-alpine glacier ice cores are useful natural archives and allow access to continuous pollution records back to the pre-industrial era. This is especially true for glacier ice cores drilled in the European Alps, which are located close to the anthropogenic emission sources. However, due to global warming glaciers are increasingly affected by melting, subsequently altering the information stored in the natural archive.
Here we show the comparison between major ion records from shallow ice cores drilled on Grand Combin (4123 m a.s.l., Swiss Alps) in 2018 and 2020. Both shallow ice cores were dated applying annual layer counting using stable isotopes and concentrations of major ions (e.g., ammonium). Excellent agreement between both records was observed for the stable isotopes in the overlapping time period 2011-2018. However, in the core collected in 2020, effects of melting were detected for the major ion concentrations before 2016. As an extreme example: sulfate is significantly depleted in the years 2011-2016 in that core, losing 61% of the ion content in comparison with the core collected in 2018. Even for ammonium, which is the most preserved with only 16 % reduction, the seasonal cycle disappeared. The elution sequence matches the results of Avak et al. (2019).
Meteorological data indicate that mean annual air temperatures of 2019 and 2020 were not significantly higher than in the previous years. Instead, we attribute the melt damage in the 2020 core to a two-week period in summer 2019 with temperatures continuously above 0°C. Our finding that such a disturbance through melting can occur in only two years emphasises the critical state of these glacier archives. Thus, preserving these archives is important and a time sensitive matter.
REFERENCES
Avak, S. E., Trachsel, J. C., Edebeli, J., Brütsch, S., Bartels‐Rausch, T., Schneebeli, M., Schwikowski, M. and Eichler, A.: Melt‐induced fractionation of major ions and trace elements in an Alpine snowpack, Journal of Geophysical Research F: Earth Surface, 124(7), 1647-1657, https://doi.org/10.1029/2019JF005026.
How to cite: Huber, C., Eichler, A., Mattea, E., Brütsch, S., Jenk, T., Gabrieli, J., Barbante, C., and Schwikowski, M.: High-alpine Glacier Record Influenced by Melting, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8040, https://doi.org/10.5194/egusphere-egu22-8040, 2022.
