cosmogenic nuclides; Lateglacial; glacier ice flow modeling; 10Be, in situ 14C, 36Cl; subglacial erosion; rockglacier; Alps; Last Glacial Maximum
Steinemann Olivia, Reitner Jürgen M., Ivy-Ochs Susan, Christl Marcus, Synal Hans-Arno (2020), Tracking rockglacier evolution in the Eastern Alps from the Lateglacial to the early Holocene, in Quaternary Science Reviews
, 241, 106424-106424.
Steinemann Olivia, Ivy‐Ochs Susan, Grazioli Sandra, Luetscher Marc, Fischer Urs H., Vockenhuber Christof, Synal Hans‐Arno (2020), Quantifying glacial erosion on a limestone bed and the relevance for landscape development in the Alps, in Earth Surface Processes and Landforms
, 45(6), 1401-1417.
Braakhekke Jochem, Ivy‐Ochs Susan, Monegato Giovanni, Gianotti Franco, Martin Silvana, Casale Stefano, Christl Marcus (2020), Timing and flow pattern of the Orta Glacier (European Alps) during the Last Glacial Maximum, in Boreas
, 49(2), 315-332.
Seguinot Julien, Ivy-Ochs Susan, Jouvet Guillaume, Huss Matthias, Funk Martin, Preusser Frank (2018), Modelling last glacial cycle ice dynamics in the Alps, in The Cryosphere
, 12(10), 3265-3285.
Ivy-Ochs Susan, Lucchesi Stefania, Baggio Paolo, Fioraso Gianfranco, Gianotti Franco, Monegato Giovanni, Graf Angela A., Akçar Naki, Christl Marcus, Carraro Francesco, Forno Maria Gabriella, Schlüchter Christian (2018), New geomorphological and chronological constraints for glacial deposits in the Rivoli-Avigliana end-moraine system and the lower Susa Valley (Western Alps, NW Italy)NEW LGM GEOMORPHOLOGY AND CHRONOLOGY IN THE WESTERN ALPS, in Journal of Quaternary Science
, 33(5), 550-562.
JOUVET GUILLAUME, SEGUINOT JULIEN, IVY-OCHS SUSAN, FUNK MARTIN (2017), Modelling the diversion of erratic boulders by the Valais Glacier during the last glacial maximum, in Journal of Glaciology
, 63(239), 487-498.
Wirsig Christian, Ivy-Ochs Susan, Reitner Jürgen M., Christl Marcus, Vockenhuber Christof, Bichler Mathias, Reindl Martin (2017), Subglacial abrasion rates at Goldbergkees, Hohe Tauern, Austria, determined from cosmogenic 10 Be and 36 Cl concentrations Subglacial abrasion rates at Goldbergkees, Hohe Tauern, in Earth Surface Processes and Landforms
, 42(7), 1119-1131.
This proposal is made up of two parts: (1) PhD1, the final two years of PhD student Olivia Kronig in the continuation of SNF project 156187, and (2) PhD2 a new project for four years. PhD1. In the first two years of her project (SNF 156187), Olivia Kronig is using detailed mapping and cosmogenic 10Be exposure dating of fossil rockglaciers (in Austria) to extract the climate signal and generate fundamental information on the timing of cold events during the Lateglacial (18,000 to 12,000 years ago) in the Alps. The second goal of her project is to use cosmogenic 10Be and 36Cl to quantify subglacial erosion rates at the Trift and Tsanfleuron glaciers in the Swiss Alps. At Trift (gneiss bedrock), she will in addition use in situ 14C in quartz to determine the length of time that the glacier covered and actively eroded the bedrock. ETH is one few institutions worldwide where the latter methodology is possible. PhD2. One of the great unknowns in paleoclimate research today is to decipher how massive changes in atmospheric circulation affected the spatial and temporal patterns of glacier growth in the Alps during the Last Glacial Maximum (LGM). Is climate the main driving force or do differences in glacier catchment hypsometry and flow path length outweigh precipitation changes in controlling glacier extent? To address this question, PhD2 will study two LGM glacier systems, the Rhine and the Toce/Ticino glaciers. The two glaciers lie directly N-S of each other with linkage in the accumulation areas in the Lukmanier Pass region. Both glacier systems lack detailed chronological information. PhD2 will reconstruct LGM ice margins through detailed fieldwork, landform analysis based on remote imagery (with high-resolution digital elevation models) and cosmogenic nuclide exposure dating. He/she will constrain the timing of the reaching of the maximum extent, the timing of recessional (re-advance) stadial moraines, and the moment of final cataclysmic withdrawal of glaciers from the forelands with cosmogenic 10Be and 36Cl boulder and depth-profile dating. The latter (36Cl) is in the developmental stage and models for depth-age calculation will be developed based on existing models. PhD2 will use the unique tool, in situ 14C in quartz, to exclude boulders from LGM ice-margin reconstructions that were actually deposited during pre-LGM glaciations but were buried or reworked. The output of PhD2, the precisely dated LGM ice margins from the two glacier systems, will serve as point of comparison for validation of ice lobe extents based on glacier modeling. PhD2 will work together with glaciologists of the VAW/ETHZ to compare paleo ice flow model results with field evidence, as well as to discuss implications for climate input parameters. The geologist-glacier modeler combination is a uniquely synergistic approach to understanding past glacier extents: i) dating and mapping provide crucial data for adjusting ice flow models and ii) modeling is the most physically realistic way (with respect to glacier behavior) to extrapolate from maxima to continuous timespans (i.e. filling the huge gaps in the geological record). This project offers a broad-based, integrated approach combining: (1) basic geological techniques (field mapping, sedimentology, petrography), (2) GIS methodologies to augment field interpretations, (3) landform dating with accelerator mass spectrometry-measured cosmogenic nuclides and (4) state-of-the-art glacier modeling through collaboration with glaciologists. The outcome of this study will yield a significant improvement in our understanding of the input climate forcings and the glacier dynamical response that leads to the pattern of glacier timing and extent N and S of the Alps during the LGM.