Dr. Stefanie Tofelde

Research experience and skills

I am generally interested in fluvial and hillslope geomorphology and the transport of sediment along sediment-routing systems or source-to-sink systems. In particular, I try to understand how information on environmental condititions or hillslope processes are translated into sedimentary signals and how those signals are potentially modified during sediment transport. I study this by combining field and laboratory techniques.

Laboratory

• Cosmogenic nuclide analysis (10Be, 26Al): physical and chemical mineral separation, ion exchange chromatography
• Biomarker (n-alkane) analysis: Compound specific isolation and stable isotope (δD, δ13C) analysis
• Physical experiments in a flume: Channel response, terrace formation and sediment-signal disruption due to changing boundary conditions

Field

• 2019: Sumatra - 2 weeks field campaign in West Sumatra for Geoelectric Surveys on fluvial floodplains.
• 2017: New Zealand - 3 weeks field campaign in the Southern Alps and Fjordlands. Sample collection in catchments and landslides for cosmogenic radionuclide analysis (10Be, 14C), grain size distribution, drone survey to generate DEMs of landslide scars.
• 2016: Argentina -3 weeks field campaign investigating catchment – alluvial fan systems in the Santa Maria Basin. Sampling of boulders for fan surface exposure dating with cosmogenic radionuclides and grain size analysis. Sampling for stable isotope analysis in biomarkers in the Pastos Grandes Basin on the Puna Plateau.
• 2015: Argentina -5 weeks field campaign including differential GPS surveys of terrace surfaces in the Toro Basin, sample collection for cosmogenic burial dating of fluvial terraces, river grain size analysis, and sampling for geochronological analysis of lake sediments (14C).
• 2014: Argentina -6 weeks field campaign to collect samples for a geochronological analysis of fluvial terraces (10Be depth profiles, volcanic ashes), catchment mean denudation rates (10Be), river grain size analysis, and collection of fluvial sediments and stream waters for stable isotope analysis in the Toro Basin.
• 2013: Argentina - 4 weeks field campaign to sample for surface exposure dating of an alluvial fan and for catchment mean denudation rates (10Be) in the Humahuaca Basin; sampling of river sediment and soil transects for stable isotope analysis in biomarkers (n-alkanes).

[12] Tofelde, S., Bernhardt, A., Guerit, L. & Romans, B., 2021. Times associated with source-to-sink propagation of environmental signals during landscape transience. Frontiers in Earth Science, 9, 227. doi: 10.3389/feart.2021.628315

[11] Savi, S., Tofelde, S., Wickert A.W., Bufe, A., Schildgen, T.F., Strecker, M.R., accepted.  Interactions between channels and tributary alluvial fans: channel adjustments and sediment-signal propagation. Earth Surface Dynamics.

[10] Bufe, A., Turowski, J. M., Burbank, D. W., Paola, C., Wickert, A. D., & Tofelde, S., 2019. Controls on the lateral channel‐migration rate of braided channel systems in coarse non‐cohesive sediment. Earth Surface Processes and Landforms, 44(14), 2823-2836.

[9] Tofelde, S., Savi, S., Wickert, A. D., Bufe, A., & Schildgen, T. F., 2019. Alluvial channel response to environmental perturbations: fill-terrace formation and sediment-signal disruption. Earth Surface Dynamics, 7(2), 609-631.

[8] D’Arcy, M., Schildgen, T.F., Strecker, M.R., Wittmann, H., Duesing, W., Mey, J., Tofelde, S., Weissmann, P., Alonso, R.N., 2019. Timing of past glaciation at the Sierra de Aconquija, northwestern Argentina, and throughout the Central Andes. Quat. Sci. Rev. 204, 37–57. 

[7] Tofelde, S., Duesing, W., Schildgen, T.F., Wickert, A.D., Wittmann, H., Alonso, R.N., Strecker, M., 2018. Effects of deep‐seated versus shallow hillslope processes on cosmogenic 10Be concentrations in fluvial sand and gravel. Earth Surf. Process. Landforms 43, 3086–3098.

[6] Tofelde, S., Schildgen, T.F., Savi, S., Pingel, H., Wickert, A.D., Bookhagen, B., Wittmann, H., Alonso, R.N., Cottle, J., Strecker, M.R., 2017. 100 kyr fluvial cut-and-fill terrace cycles since the Middle Pleistocene in the southern Central Andes, NW Argentina. Earth Planet. Sci. Lett. 473, 141–153.

[5] Savi, S., Schildgen, T.F., Tofelde, S., Wittmann, H., Scherler, D., Mey, J., Alonso, R.N., Strecker, M.R., 2016. Climatic controls on debris-flow activity and sediment aggradation: The Del Medio fan, NW Argentina. J. Geophys. Res. Earth Surf. 2424–2445.

[4] Rohrmann, A., Sachse, D., Mulch, A., Pingel, H., Tofelde, S., Alonso, R.N., Strecker, M.R., 2016. Miocene orographic uplift forces rapid hydrological change in the southern central Andes. Sci. Rep. 6, 35678. 

[3] Nieto-Moreno, V., Rohrmann, A., van der Meer, M.T.J., Sinninghe Damsté, J.S., Sachse, D., Tofelde, S., Niedermeyer, E.M., Strecker, M.R., Mulch, A., 2016. Elevation-dependent changes in n-alkane δ D and soil GDGTs across the South Central Andes. Earth Planet. Sci. Lett. 453, 234–242. 

[2] Schildgen, T.F., Robinson, R.A.J., Savi, S., Phillips, W.M., Spencer, J.Q.G., Bookhagen, B., Scherler, D., Tofelde, S., Alonso, R.N., Kubik, P.W., Binnie, S.A., Strecker, M.R., 2016. Landscape response to late Pleistocene climate change in NW Argentina: Sediment flux modulated by basin geometry and connectivity. J. Geophys. Res. Earth Surf. 121, 392–414. 

[1] Schwanghart, W., Bernhardt, A., Stolle, A., Hoelzmann, P., Adhikari, B.R., Andermann, C., Tofelde, S., Merchel, S., Rugel, G., Fort, M., 2015. Repeated catastrophic valley infill following medieval earthquakes in the Nepal Himalaya.Science (147-150). 351, 1–9.