- Project: Field Campaign Norway | COOLER Project.
- Project date: 17 July, 2022 – 27 July, 2022
- Team members: Peter van der Beek, Cody Colleps, Maxime Bernard, Julien Amalberti and Isabel Wapenhans
Overview  Last summer (2022) the COOLER team flew to the north to reach the spectacular glacial valleys of the Jostedalsbreen park in Norway! Not only the beauty of this landscape brought us there (see photos), but interesting and unresolved scientific questions as well.
Norwegian topography has undoubtedly been shaped by prolonged glaciations during the Late Cenozoic. As a result, present-day topography is deeply incised by U-shaped valleys, and show spectacular fjords. More controversial is to whether attribute the concomitant high-elevated plateaus as a product of glacial erosion or considering them as being formed before the main glaciations. In the most recent years, some research argued in favour of the former hypothesis, but this is still highly debated up to date. If so, it would mean that glacial erosion has been more significant than previously thought, as well as its role on climate cooling through the transport and the burial of atmospheric carbon into the sedimentary basins found offshore.
In addition to the above problematic, two others remain. First, the precise timing of the glacial incision along with the formation of the deep valleys and fjords is not well constrained and range from ~11 down to ~1 Ma. However, constraining this timing is crucial to set upper limits on induced glacial erosion rates. Second, it is still unclearing to what extend tectonic uplift rates control the spatial and temporal distribution of glacial erosion. Numerical models predict that glacial erosion should increase with tectonic uplift rate but also be shifted toward lower elevations. Furthermore, while numerical models show headward propagation of glacial erosion which is supported by field data, the latter also show downward propagation of erosion. In all cases, we lack field data to constrain the outcome of numerical models. In Norway, tectonic uplift rates are argued to be low for, at least, the past 5 Myrs, which can be compared with e.g., the North-Central Alps where uplift rates are higher (see Field campaign Switzerland).
To investigate all the previously mentioned questions, we will use an approach combining apatite (u-Th)/He and 4He/3He thermochronometry analyses, with numerical modelling of glacial erosion (iSOSIA) and thermochronological data (Pecube). With this approach we hope to add constraints on (1) the pre-glacial topography of southern Norway, (2) the spatial and temporal distribution of glacial erosion through its record in the thermochronological data, and (3) the glacially-induced erosion rates in comparison with pre-glaciations times.