Azimuthal anisotropy in the wider Vienna Basin region: A proxy for the present-day stress field and deformation
- Author(s)
- Sven Schippkus, Dimitri Zigone, Götz Bokelmann,
- Abstract
We infer seismic azimuthal anisotropy from ambient-noise-derived Rayleigh waves in the wider Vienna Basin region. Cross-correlations of the ambient seismic field are computed for 1953 station pairs and periods from 5 to 25 s to measure the directional dependence of interstation Rayleigh-wave group velocities. We perform the analysis for each period on the whole data set, as well as in overlapping 2°-cells to regionalize the measurements, to study expected effects from isotropic structure, and isotropic-anisotropic trade-offs. To extract azimuthal anisotropy that relates to the anisotropic structure of the Earth, we analyse the group velocity residuals after isotropic inversion. The periods discussed in this study (5-20 s) are sensitive to crustal structure, and they allow us to gain insight into two distinct mechanisms that result in fast orientations. At shallow crustal depths, fast orientations in the Eastern Alps are S/N to SSW/NNE, roughly normal to the Alps. This effect is most likely due to the formation of cracks aligned with the present-day stress-field. At greater depths, fast orientations rotate towards NE, almost parallel to the major fault systems that accommodated the lateral extrusion of blocks in the Miocene. This is coherent with the alignment of crystal grains during crustal deformation occurring along the fault systems and the lateral extrusion of the central part of the Eastern Alps.
- Organisation(s)
- Department of Meteorology and Geophysics
- External organisation(s)
- Université de Strasbourg
- Journal
- Geophysical Journal International
- Volume
- 220
- Pages
- 2056–2067
- No. of pages
- 12
- ISSN
- 0956-540X
- DOI
- https://doi.org/10.1093/gji/ggz565
- Publication date
- 12-2019
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105122 Seismic
- Keywords
- ASJC Scopus subject areas
- Geochemistry and Petrology, Geophysics
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/75ba6c56-bd31-43ac-a5ac-79c9ab357180