FRAGILE EARTH: Geological Processes from Global to Local Scales and Associated Hazards (4-7 September 2011)

Paper No. 3
Presentation Time: 08:30-18:00


EVERS, Serjoscha, ENGELMANN, Oliver and HOFMANN, Florian, Department of Earth and Environmental Sciences, Geology, University of Munich, Luisenstr. 37, Munich, 80333, Germany,

Tectonic classes at the undergraduate level are difficult because they require visualization of complex 3-D-structures. In the Bachelor of Geosciences program at the University of Munich, we had the opportunity to learn the structure of orogenic belts through hands-on experiments.

As 3rd semester students we performed different accretionary wedge models (after Davis et al., 1983) to compare the resulting structures with natural examples. We took photographs of the side wall and in top view. We measured the deformed features and surface slope. The pictures were also processed with Particle Image Velocimetry (PIV) software to visualize deformation. The surface slope converged towards a stable value. The analysis of PIV pictures showed tectonic structures such as fault-propagation folds. We created tectonic maps from the surface morphology and schematic tectonic profiles. We measured the angle between the surface slope and décollement horizon using our data and those of other students' experiments. The results were in agreement with Critical Taper Theory. We compared the tectonic pattern in our experiments with geological maps of natural accretionary wedges and wrote up our results as a scientific paper.

We found the analog modeling experiments very helpful to understand the nature of tectonic structures. The experimental work motivated us to go significantly beyond material discussed in class. During the writing process we gained essential scientific skills such as literature research, data processing and documentation. Based on our experience we highly recommend analog modeling as a teaching tool for undergraduate geology classes. The experiments require a laboratory with sandbox models, software for data analysis and supervision. The analog models are not commercially available and need to be built. Experiments take a few hours. Data analysis and paper writing requires a semester-based 3-credit-hour class. The paper needs a clear framework, but also enough space for the student to work creatively and independently.

We experienced analog modeling as an excellent way to learn the scientific method and deepen our understanding of tectonics. Therefore we would like to engage other students and geology instructors to introduce analog modeling into the scientific curriculum.