Seismic imaging of the newly discovered Sub-Lithospheric Discontinuity (SLD) in the larger Alpine region

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Kind et al. (2016, see attachment) discovered with seismic receiver functions below the in central Europe about 100 km deep lithosphere-asthenosphere boundary (LAB) a new so far unknown negative (downward velocity decrease) discontinuity which they called Sub-Lithospheric Discontinuity (SLD). The SLD is in the Pannonian Basin about 150 km deep, reaches below the Bohemian Massif 300 km and jumps abruptly upward to 200 km below the north German Basin and the east European craton. So far there exists no generally accepted geological interpretation of the SLD. Kind et al. (2016) observed below the eastern Alps the LAB down to about 150 km depth without being able to resolve the subduction direction. On the whole our observations and others show that the S-receiver function technique is probably the method with highest resolution for upper mantle discontinuities. The SLD under the Alpine region has been observed only with low resolution with the existing data of the permanent stations. The large density of the AlpArray stations should be able to resolve the question if the central European SLD is connected to the east European craton or to the from the south accreting terranes. In particular we will study the topography of the SLD and other upper mantle discontinuities below the larger Alpine region which is important for studies of the geodynamic relations. In addition we will study the sharpness of the seismic discontinuities with the help of theoretical seismograms, which is important for the petrological interpretation. Finally we plan to compare receiver function velocity model with such observed with surface wave tomography to ensure correctness of the models.These projects fit into the first Research Theme RT1 'Reorganisation of the Lithosphere during Mountain Building'and in the data collecting Activity Fields: AF-A (UNIBRAS/DSERBA), AF-B (LOBSTER), AF-C (Swath C: From Apennines to Alps) AF-D (Swath D: across central and easter Alps).