Halftime reports from Erg Chebbi
Feb 25th, 2020 by Katharina Anders
After three days of hard work in the field, Sunday was halftime workshop at HeidelErg. with diverse topics all around dunes, with and beyond the data collected in ErgChebbi.
Manuel Herzog introduced the first results from the geophysical measurements with regards to dune stratification. Ground penetrating radar in combination with Electrical Resistivity Tomography already shows promising results. The full analysis requires topographical correction, which relies on GNSS measurements of the transects. Katharina Anders presented the first version of the 3D model of the star dunes in connection with repeat GNSS measurements of the dunes crests. Master student Karl Wutzer showed possibilities to discriminate dune sands based on shape, color and especially grain size, for which he develops a new approach using image analysis.
Moreover, two researchers who joined the field course, presented their work to the group. Mateusz Kryger (University of Cologne) presented his work on numerical modeling of dunes. This stimulated a discussion about uni- or bi-modal wind directions in order to understand the formation of specific dune forms, such as barchans and longitudinal seif dunes.
Merve Seçkin-Kryger (German Aerospace Center) gave insight into her experiments in a laboratory wind tunnel, where she uses coated hollow microspheres to build up cm-size barchan dunes. These experiments help to understand dune forms we observe on Earth as well as on other planets, e.g. Mars.
Presenting results of geophysical measurements
Numerical modeling of dunes
Dune formation via wind tunnel experiments
Grain-based"crime scene" investigation