Comparison of the Crustal Structure of the Eastern Alps and Western Carpathians by Receiver Function Imaging

Comparison of the Crustal Structure of the Eastern Alps and Western Carpathians by Receiver Function Imaging José Andrés Díaz Giraldo The Eastern Alps and the Western Carpathians are two adjacent segments of the Alpine–Carpathian orogenic system, sharing a common geodynamic history linked to the closure of the Alpine Tethys and the collision between the European and Adriatic plates. Despite this shared evolution, their crustal architectures differ significantly, reflecting contrasting tectonic processes. This thesis aims to investigate and compare the crustal structure of these two mountain belts using teleseismic receiver function imaging, with a particular focus on the Eastern Alps. A total of 57 broadband seismic stations located between latitudes 45° and 51° and longitudes 13.18°–13.56° were used for data acquisition in the Eastern Alps. Receiver Functions (RFs) were computed from over 800–1200 global teleseismic events per station. Of these, a subset of 48 stations and in average 97 high quality events per station were selected for Common Conversion Point (CCP) migration. The resulting seismic images highlight key crustal and upper mantle features across the region, including the Moho discontinuity, intracrustal reflectors, and the Tauern Window. The CCP profiles reveal a thickened crust beneath the Eastern Alps, with a diffuse, vertically extensive Moho zone beneath the Tauern Window—interpreted as a crustal root and exhumed European lower crust. In contrast, the Western Carpathians, based on previous studies, show a thinner crust, clearer Moho steps, and no evidence for a comparable exhumation wedge. These contrasting features suggest a fundamentally different orogenic architecture: a bivergent structure in the Eastern Alps versus a more asymmetric crustal configuration in the Western Carpathians. This work represents a first step toward a unified seismic imaging approach for both regions, using consistent processing methods to enable direct comparison. Although the CCP images are preliminary and require further refinement, they already provide new insights into the deep structure and tectonic evolution of the Eastern Alps, and serve as a foundation for future comparative studies across the Alpine–Carpathian system. Keywords: Eastern Alps, Western Carpathians, Tauern Window, Pieniny Klippen Belt, Receiver Functions, Crustal Structure, Moho, Lithospheric Imaging