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The European Alps, formed by the interactions between the European and Adriatic plates, is a unique geological structure that has been extensively studied over the past decades. Despite numerous active and passive seismic investigations in the past, the crustal structure across the whole Alpine domain is somehow limited - mainly due to the limited number of seismometers available. The deployment of the AlpArray Seismic Network provides, which consisted of around 600 broadband seismometers and was operational from early 2016 till mid-2019, offers a unique opportunity to further update the current knowledge of the crustal structure beneath the European Alps by employing Receiver function (RF) analysis. RF method can provide an efficient way to image the structures and the discontinuities within the uppermost part of the Earth. We use teleseismic earthquakes with M≥5.5 and MAs of abstract submission, we are in the process of calculating the RFs. We also intend to perform a time to depth migration, in a 3D spherical coordinate system, to the RFs. This methodology, together with unprecedented data coverage, will provide us with migrated profiles that will image the structure of the crust and map the Moho depths at a great level of detail.

Receiver function analysis is applied to the western part of the Pannonian Basin, a rather complex region both geologically and geodynamically. Previous receiver function analyses in this region had to deal with much smaller station density and time span than those available to us. In the analysis we used the data of some 48 seismological stations. These include not only the permanent stations from Hungary and permanent stations from neighbouring countries (Slovakia and Slovenia), but also the temporary broadband stations that were installed within the framework of the AlpArray project. Having applied rather strict manual quality control on the calculated radial receiver functions we stacked the receiver functions. Using the H–K grid search method we determined the Moho depth and the Vp/Vs ratio beneath the seismological stations in the western part of the Pannonian Basin. The unprecedented density of the AlpArray network, combined with the permanent stations, allowed us to derive high resolution Moho and Vp/Vs maps for the West Pannonian Basin, together with uncertainty estimates. Our preliminary results agree well with previous studies and complement them with finer details on the Moho topography and crustal thickness.

Receiver function analysis is performed for the easternmost part of the Pannonian Basin and across the Southern Carpathians, a geologically and geodynamically complex region featuring microplates, mountain belts, and locally deep sedimentary basins. We exploited seismological data of 56 stations including temporary broadband stations of the South Carpathian Project (SCP) and two permanent stations in Hungary. We calculated P-to-S receiver functions to determine the variation of Moho depth across the basin and the mountains along a NW–SE-oriented swath about 600 km long and 200 km wide. We applied threefold quality control on the raw and the processed data. The Moho depth was determined by two independent approaches, common conversion point migration and H-K grid search method. The determined Moho depths show shallow values between the AlCaPa and the Tisza-Dacia blocks, with typical depths between 22 and 28 km, and the shallowest depths in the area of eastern Pannonian Basin. We could estimate the Moho depth beneath one station in the Mid-Hungarian Zone, between the AlCaPa and the Tisza-Dacia blocks. The crust was thicker under the Apuseni Mountains (28–32 km), and in the investigated region, the Moho was deepest beneath the Southern Carpathians (33–43 km). We observed a southeastward crustal thickness increase, and we presented an interpolated Moho map over the area of study.