EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Establishing the eastern alpine-dinaric transition with teleseismic receiver functions: Evidence for subducted European Crust

Stefan Mroczek1,2, Frederik Tilmann1,2, Jan Pleuger2, Xiaohui Yuan1, Ben Heit1, and the SWATH-D and AlpArray Working Groups*
Stefan Mroczek et al.
  • 1GFZ Potsdam, Seismology, Potsdam, Germany (
  • 2Institute for Geological Sciences, Freie Universität Berlin, Berlin, Germany
  • *A full list of authors appears at the end of the abstract

The dense SWATH-D seismic network in the Central-Eastern Alps gives an unprecedented window into the collision of the Adriatic and European plates. We apply the receiver function method to the SWATH-D stations, covering approximately the area from 45-49°N and 10-15°E, supplemented by the AlpArray Seismic Network and the EASI data. A switch in the subduction polarity between the Central Alps (European subduction) and the Dinarides (Adriatic subduction) had been previously suggested to occur below the Eastern Alps but its location and nature are heavily debated. To probe this hypothesis we produce a high resolution Moho map of the Eastern Alps and derive Moho depths from joint analysis of receiver function images of direct conversions and multiple reflections, which enables us to map overlapping discontinuities. Contrary to the hypothesis suggesting the subduction of Adriatic lithosphere in the Eastern Alps, we observe the European Moho to be underlying the Adriatic Moho up to the eastern edge of the Tauern Window (~13.5°E). East of this longitude, a sharp transition from underthrusting European to a flat and thinned crust associated with Pannonian extension tectonics occurs, which is underthrust by both European crust in the north and by Adriatic crust in the south. The northeast-directed underthrusting of Adriatic lithosphere smoothly transitions to subduction below the northwestern Dinarides.

Teleseismic tomography and receiver functions show different aspects of the same system (velocity anomalies versus velocity gradients) making direct comparisons difficult. The common conversion point stacks and Moho picks show good agreement with the tomography however some key differences remain. In particular, teleseismic tomography indicates high velocity anomalies detached from the crust east of ~13°E while receiver functions, in particular the transverse component, show some evidence for connection with a continuous interface going to depth.

SWATH-D and AlpArray Working Groups:

Members of the SWATH-D Working Group who are not otherwise co-authors are M. Weber and C. Haberland. The complete member list for the AlpArray Working group can be found at

How to cite: Mroczek, S., Tilmann, F., Pleuger, J., Yuan, X., and Heit, B. and the SWATH-D and AlpArray Working Groups: Establishing the eastern alpine-dinaric transition with teleseismic receiver functions: Evidence for subducted European Crust, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8790,, 2022.