ALBERT

Description: We use seismic waveform data from the AlpArray Seismic Network and three other temporary seismic networks, to perform receiver function (RF) calculations and time-to-depth migration to update the knowledge of the Moho discontinuity beneath the broader European Alps. In particular, we set up a homogeneous processing scheme to compute RFs using the time-domain iterative deconvolution method and apply consistent quality control to yield 112 205 high-quality RFs. We then perform time-to-depth migration in a newly implemented 3D spherical coordinate system using a European-scale reference P and S wave velocity model. This approach, together with the dense data coverage, provide us with a 3D migrated volume, from which we present migrated profiles that reflect the first-order crustal thickness structure. We create a detailed Moho map by manually picking the discontinuity in a set of orthogonal profiles covering the entire area. We make the RF dataset, the software for the entire processing workflow, as well as the Moho map, openly available; these open-access datasets and results will allow other researchers to build on the current study. How to cite. Michailos, K., Hetényi, G., Scarponi, M., Stipčević, J., Bianchi, I., Bonatto, L., Czuba, W., Di Bona, M., Govoni, A., Hannemann, K., Janik, T., Kalmár, D., Kind, R., Link, F., Lucente, F. P., Monna, S., Montuori, C., Mroczek, S., Paul, A., Piromallo, C., Plomerová, J., Rewers, J., Salimbeni, S., Tilmann, F., Środa, P., Vergne, J., and the AlpArray-PACASE Working Group: Moho depths beneath the European Alps: a homogeneously processed map and receiver functions database, Earth Syst. Sci. Data, 15, 2117–2138, https://doi.org/10.5194/essd-15-2117-2023, 2023.

Description: We perform a comprehensive P-to-S and S-to-P receiver function analyses to determine the depth of lithospheric discontinuities in the Eastern Alps, Pannonian Basin, Carpathians, and the Dinarides. The Pannonian Basin of Central Europe hosts thick sedimentary deposits of up to 7 km thickness in extensional half-graben geometries overlying the crystalline orogenic basement. Prior to this study, the mapping of the seismic discontinuities in the lithosphere beneath the investigated area was not uniform and the estimated depth values bore non-negligible uncertainties. Owing to the combined, dense station coverage of more than 380 seismological stations we can achieve hitherto unprecedented spatial resolution. Our study is based on two decades (2002–2022) of broadband waveforms with uniform automatic waveform processing and quality control procedures. This detailed procedure provides new geological and geophysical information about the lithosphere of the region. The obtained results allow us to infer a 3D lithospheric structural model of the region. We have developed a new interpolation and visualization algorithm. We mapped the thickness of the main crustal layers and the lithosphere, together with an estimate of their uncertainties. We present the sedimentary thickness map, the first Conrad depth map and an improved, detailed Moho map, the first upper and lower crustal thickness maps, as well as the lithospheric (Lithosphere-Asthenosphere-Boundary and Mid-Lithospheric-Discontinuity) thickness map obtained from receiver function analysis. We show migrated Common Conversion Point cross-sections beneath the Pannonian Basin and Carpathians, and the Eastern Alps–Pannonian Basin transition zone. Finally, we compare and jointly interpret the results of the receiver functions with previous geophysical investigations and seismic tomography models.