Alpine Ice Cores and Ground Penetrating Radar: Combined Investigations for Glaciological and Climatic Interpretations of a Cold Alpine Ice Body
The accurate interpretation of ice cores as climate archives requires detailed knowledge about the glaciological environment.We investigate the potential of ground penetrating radar (GPR) surveys to obtain information about the internal structure of a cold alpine ice body to improve theinterpretation of two ice cores containing long-term climate information from Colle Gnifetti, Swiss-Italian Alps, retrieved as part of the ALPCLIM project.The GPR profiles connect several drill sites, parallel and perpendicular to the flow line, yielding a 3D picture of the subsurface.Observed internal reflection horizons are of isochronic origin, faciliating the transfer of age-depth relations between the ice cores.A third ice core record is used as independent means to estimate the accuracy of the GPR results in respect to flow modeling, based on glaciological surface data,which was used before for climate analysis of the ice cores.Our results demonstrate that GPR data is a mandatory tool for alpine ice core studies, as they allow to map major transitions in physical-chemical properties,transfer age-depth relations between sites, complement ambiguous peaks in core records for interpretation, and establish a detailed picture of the flow regimesurrounding the climate archive.