The northern Alpine foreland is one of the most seismically active regions in Central Europe. Due to the deformation of the Alps and the related tectonic stresses a lot of faults exist and are (re-)activated. However not all of them are seismically active. The aims of the Stress Transfer Project are to map and to identify the active faults by means of neotectonics and seismicity and to determine the stress field. Stress Transfer is embedded in the AlpArray experiment and the DFG SPP 4-D Mountain Building.
At the moment the focus is on the Albstadt Shear Zone (ASZ), an approx. 20-30 km long, N-S striking fault with left-lateral strike slip close to the town of Albstadt on the Swabian Jura. There strong earthquakes occurred in 1911, 1943, 1969/70, and 1978. As there is no evidence for surface rupture, the nature of the Albstadt Shear Zone can only be studied by its seismicity.
To characterize the ASZ we currently complement the earthquake catalog of the Seismological Service of the state of Baden-Württemberg with additional seismic phase onsets. For the latter we use the station network of AlpArray as well as five additional recently installed seismic stations from the KArlsruhe BroadBand Array. In addition, we invert for a new seismic minimum 1D-velocity model of the study region and calculate focal mechanisms. All this information is used to determine the potential rupture planes and a possible segmentation of the ASZ. We thank the Landeserdbebendienst in Freiburg for using their data (Az. 4784//18_3303).