We use ambient noise tomography to investigate the crust and uppermost mantle structure beneath the Carpathian–Pannonian region of Central Europe. Over 7500 Rayleigh wave empirical Green's functions are derived from interstation cross-correlations of vertical component ambient seismic noise recordings (2005–2011) using a temporary network of 54 stations deployed during the South Carpathian Project (2009–2011), 56 temporary stations deployed in the Carpathian Basins Project (2005–2007) and 100 permanent and regional broad-band stations. Rayleigh wave group velocity dispersion curves (4–40 s) are determined using the multiple-filter analysis technique. Group velocity maps are computed on a grid of 0.2° × 0.2° from a non-linear 2-D tomographic inversion using the subspace method. We then inverted the group velocity maps for the 3-D shear wave velocity structure of the crust and uppermost mantle beneath the region. Our shear wave velocity model provides a uniquely complete and relatively high-resolution view of the crustal structure in the Carpathian–Pannonian region, which in general is validated by comparison with previous studies using other methods to probe the crustal structure. At shallow depths (30 km are relatively fast, presumably related to shallowing of the Moho consequent on the extensional history of the Pannonian region.

Summary. Source scaling properties are studied for the intermediate-depth seismic nest in the Vrancea region, Romania, which has been the source of many destru