In this example, we reproduce the forward modelling strategy from [Valla-et-al-2012] and predict AHe and 4He/3He data from the Rhone valley, Switzerland. There, [Valla-et-al-2012] inferred a ~90-100% relief increase in the last 1.0 ± 0.5 Ma, coinciding with intensification of glaciations (i.e., 100 kyr cycles). We choose here to model the topographic scenario based on the AHe and 4He/3He data from the Visp area (i.e., see Valla et al., 2012, for more details). However, we choose to incorporate an extended dataset that includes AFT data for demonstration.
We see here that we fairly reproduce the AFT and AHe ages from the Visp area. We also fairly reproduce the 4He/3He spectrum from sample VIS-07 located at the valley bottom. However, the predictions are off from observations in the Sion area. This is due to the simplified topographic scenario used here, where incision of valley starts everywhere at the same time. However, the data might be more consistent with a headward propagation of glacial erosion as inferred from [Sternai-et-al-2013].



Sternai, P., Herman, F., Valla, P. G., & Champagnac, J. D. (2013). Spatial and temporal variations of glacial erosion in the Rhône valley (Swiss Alps): Insights from numerical modeling. Earth and Planetary Science Letters, 368, 119-131.

[Valla-et-al-2012] (1,2)

Valla, P. G., van der Beek, P. A., Shuster, D. L., Braun, J., Herman, F., Tassan‐Got, L., & Gautheron, C. (2012). Late Neogene exhumation and relief development of the Aar and Aiguilles Rouges massifs (Swiss Alps) from low‐temperature thermochronology modeling and 4He/3He thermochronometry. Journal of Geophysical Research: Earth Surface, 117(F1).