Determining the age distribution of Colle Gnifetti, Monte Rosa, Alps, by combining ice cores, ground-penetrating radar and a simple flow model

• Published in: Journal of Glaciology
• Main Authors: Konrad, Hannes, Bohleber, Pascal, Wagenbach, Dietmar, Vincent, Christian, Eisen, Olaf
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: INT GLACIOL SOC 2013
• Subjects: ice core; Journal of Glaciology
• Online Access: https://epic.awi.de/id/eprint/25894/; https://hdl.handle.net/10013/epic.40891

Ice cores from cold Alpine glaciers may provide unique paleoclimate information fromnon-polar latitudes. We explore the three-dimensional internal age distribution of the small cold glaciersaddle (Colle Gnifetti, Monte Rosa, Italy/Switzerland) to compare the age/depth relations from fourlocal deep ice cores. Tracking isochronous refection horizons detected by ground-penetrating radar(GPR) among the core locations reveals consistent dating up to 80 yearsbp. This approach is confned torecent ages,duetothelackofclearrefectionsbelowthefrn/icetransition.Weattempttoovercomethislimitation by including a two-dimensional fow model adapted to the GPR-derived surface accumulationand ice thickness distribution. Modeled and GPR isochrones are compared, indicating agreement inshape but featuring a potential offset of 0–3.5m. The modeled isochrones are interpolated to the corearray with ages assigned according to the ice-core datings. The resulting age distribution is consistentup to 110 yearsbp, with age uncertainties increasing from 7 to>80 years in the lower half of the ice.This combination of methods is novel for Alpine sites and may be adapted for spatial extrapolation ofice properties other than age