Sediment Thickness of European Basins Inferred from P-to-S Receiver Functions

Sediment thickness is a key parameter in seismological studies, influencing seismic wave propagation, ground-motion amplification, and the interpretation of crustal and upper-mantle structure. Thick sedimentary cover, characterized by low seismic velocities, can strongly bias tomographic inversions if not properly accounted for. While receiver-function–based approaches have proven effective for estimating sediment thickness in Australia and North America, their systematic application across Europe has remained limited.

Here we test and refine a P-to-S receiver function (PRF)–based method for estimating sediment thickness in Central and Eastern Europe, focusing on major sedimentary basins including the Pannonian Basin, where sediment thickness locally exceeds 8 km. Additional analyses are carried out in the Vienna and Transylvanian basins to capture a wider range of geological settings. This method is controlled and compared to data derived from reflection seismic profiles and deep borehole data from the basins.

Using teleseismic PRFs, we measure the delay time of the P-to-S converted phase at the sediment–basement interface and relate it to sediment thickness through empirical fitting. The fitting accounts for multiple controlling parameters, including PRF delay time, basin-specific seismic velocity characteristics, and regional geological context. The study region represents an exceptional natural laboratory, as dense temporary and permanent seismic networks (e.g., AlpArray, PACASE, and AdriaArray) have been operating for nearly a decade, providing unprecedented data coverage.

Our results demonstrate that PRF-derived delay times reliably capture first-order variations in sediment thickness across structurally complex European basins. Our long-term goal is to extend this approach to the entire European continent, enabling a consistent, low-cost framework for mapping sediment thickness across diverse tectonic environments.