At the end of March Dr. Anna Schoch-Baumann, Manon Cramer and Dr. Rainer Bell from the RG Schrott conducted fieldwork in Obergoms, Switzerland, together with four Master students Julia Feth, Aurel Vidali, Hovhannes Amirdschanjan and Linda Weis. The aim was to investigate the formation of outsize fans and their geomorphological impact on the Upper Rhone Valley. The work directly builds on the doctoral research of Dr. Anna Schoch-Baumann, which focused on sediment dynamics and their role in shaping alpine valley systems.
Data collection was done using geophysical methods, including electrical resistivity tomography (ERT) and ground penetrating radar (GPR). These methods were applied to investigate the lowermost of the three outsize fans, which has not previously been studied at all. They were also used to examine the transition zone between the previously studied uppermost fan and the adjacent valley-floor deposits, where data coverage has so far been limited, as well as the fluvial deposit itself. Soil samples were extracted at four different locations using the ram core drilling method, reaching depths up to 10 meters. Theses samples are going to be analyzed in the laboratory for grain size distribution, organic matter content as well as 14C dating.
The combination of the different methods and their results allow key research questions to be addressed, such as if the uppermost fan led to a blockage of the sediment and fluvial system in the Upper Rhone Valley or whether the internal structure of the lowermost outsize fan resembles the one analyzed by Anna Schoch-Baumann.
A sudden winter outbreak led to more difficult conditions with cold temperatures and a lot of snow that required shoveling to insert the electrodes into the soil for the ERT measurement. However, the snow had its advantages, making GPR handling easier and providing a beautiful landscape to work in :)
For more details to this research, see the dissertation of Anna Schoch-Baumann linked below.
