Active Faulting in Lake Constance (Austria, Germany, Switzerland) Unraveled by Multi-Vintage Reflection Seismic Data

Probabilistic seismic hazard assessments are primarily based on instrumentally recorded and historically documented earthquakes. For the northern part of European Alpine Arc, slow crustal deformation results in low earthquake recurrence rates brings up necessity to extend our perspective beyond existing catalog. The overdeepened basin Lake Constance (Austria, Germany, Switzerland), located within North-Alpine Molasse Basin, is investigated as an ideal (neo-) tectonic archive. lake surrounded by major structures constrained via North Front South, Jura fold-and-thrust belt West, Hegau-Lake Graben System North. Several fault zones reach such St. Gallen Fault Zone, a reactivated basement-rooted normal fault, active during several phases from Permo-Carboniferous Mesozoic. To catalog potentially zones, we compiled extensive 445 km multi-channel reflection data 2017, complementing moderate-size GI-airgun survey 2016. two datasets reveal complete Quaternary trough its sedimentary infill upper Miocene bedrock. They additionally complement vintages that mass-transport deposit chronology Mesozoic structures. compilation 2D allowed investigating stratigraphy underlying bedrock Constance, shaped multiple glaciations. sections revealed 154 indications Obersee Basin 39 Untersee Basin. Their interpretative linkage 23 five planes, respectively. One traceable Cenozoic bedrock, associated with prominent offset bottom multibeam bathymetric map. Across this area, high-resolution single channel was acquired transect short cores retrieved displaying significant sediment thickness changes across seismically mapped trace surface-rupture related turbidite, all indicating repeated activity likely seismogenic strike-slip faulting component. We interpret northward continuation previously described onshore 3D data.