OROG3NY is a research project focusing on a number of key questions of mountain building. On one hand on the 3D structures that define a mountain belt, their variations in depth as well as along the arc, and the role of the lower crust. On the other hand on the processes that shape an orogen, such as earthquakes and metamorphic evolution. The project targets questions in the Himalayas and the European Alps with geophysical tools, such as seismology, gravimetry and numerical modelling, and include elements of petrology.
The project is funded by SNF (see summary in the P3 database), and hosted at the ISTE at UNIL.
We are interested in structures and processes governing the evolution of mountain belts, and to solve related questions using geophysical tools. Our work focuses mostly on the following projects:
- Orogenic structures are rarely cylindrical: the closer one looks the more spatial variability one sees. Therefore there is an inevitable need to improve structural images towards 3D and higher resolution. A methodology to create 3D shear-wave velocity models from converted waves (receiver function) is a promising tool to characterize the crust and to identify the main lithologies. Leonardo Colavitti is developing a new approach in his Ph.D. thesis.
- A special feature of the Alps is the Ivrea-Verbano Zone, where the Ivrea Geophysical Body outcrops at the surface. Analysing these lower crustal rocks is of primary interest for understanding the structure and evolution of the crust-mantle transition zone, and of this segment of the Alps. Matteo Scarponi‘s Ph.D. research focuses on this area with a temporary seismological experiment and gravity campaigns to improve the spatial coverage, from which 3D models can be constructed. His work contributes to the preparation of the ICDP project DIVE.
- Metamorphic reactions affect rocks in the crust in various ways and strongly influence their geodynamic evolution. While these phase changes are well understood in the laboratory and at the rock sample scale, large scale observations from geophysics are scarce. As his post-doc research, Celso Alvizuri focuses on geophysical signals related to metamorphism to decipher more information about their large-scale characteristics and mechanism.
- AlpArray is a European initiative to advance our understanding of orogeny and its relationship to other geodynamic processes and hazards in the Alps-Apennines-Carpathians-Dinarides system. The project integrates high-resolution geophysical imaging of 3D structures and physical properties of the lithosphere with focus on a high-end seismological array. György Hetényi is involved both in the research and in the general management of the project.
- Bhutan, a kingdom in the Eastern Himalayas, is a blank spot on the geophysical map of the region. In the past 5 years György Hetényi was leading two geophysics projects to geophysically map Bhutan (using gravity anomalies, and a broadband seismology array in project GANSSER), and participated in a number of other projects with colleagues from Montpellier (see report and interview).
- The Eastern Alpine Seismic Investigation (EASI) project is carried out as the first “AlpArray Complementary Experiment”, featuring a north-south array of 55 broadband stations along ca. 13.4°E across the Alps. With this György Hetényi and colleagues in Zürich, Prague and Vienna aim to characterize how Europe and Adria plate lithospheres meet at depth, especially the gap between their Mohos and the role of their lower crust.
- Funded by a Swiss Government Excellence Scholarship, Shiba Subedi puts his effort at teaching Nepali schools about earthquakes and related hazard, and installs a 20-station low-cost seismic network for this purpose and also for crowdsourcing. Besides that, he also focuses on the crustal structure of Western Nepal using receiver function, to finalize his M.Sc. project.
Beyond these main themes, we work together with other researchers on various topics, mostly related to orogeny, geophysics and petrology.