Late Pleistocene to Holocene paleoseismicity and seismic hazard of the southern Feldbiss Fault (Lower Rhine Graben, Germany)

Abstract The Lower Rhine Graben (LRG) is one of the most seismically active intraplate areas in the low-strain region of central Europe. Records of significant historical earthquakes in the LRG demonstrate the potential for future damaging events that pose a notable hazard to the region´s dense population and extensive industrial infrastructure. Although previous paleoseismic investigations have focused on larger faults in the LRG, the southern Feldbiss Fault has not been studied despite recent seismic activity. We address this gap through paleoseismic investigations integrating high-resolution LiDAR-based DEM analysis, shallow geophysics, shallow percussion drilling, and paleoseismic trenching. Paleoseismic trenches exposed several steeply (70°–80°) ENE-dipping normal fault splays of the Feldbiss Fault. The stratigraphy indicates a cumulative total displacement of 1.3 ± 0.1 m during the late Pleistocene and Holocene, corresponding to four distinct surface-rupturing events. These events are associated with estimated magnitudes ranging from M 5.9 to 6.6 and a slip rate of 0.026 ± 0.007 mm/yr since 26.8 ± 2.0 ka. The youngest surface-rupturing event occurred in historical times (< 1728–1785 CE) and may be associated with the 1755/1756 CE Düren earthquake series. The absence of aseismic creep and the identification of episodic faulting since the late Pleistocene indicate that the Feldbiss Fault remains capable of coseismic rupture. Although the southern continuation of the LRGs faults toward the Eifel is still debated, our study demonstrates that the terminal sections (tips) of large faults can also rupture during c. M 6 events in a low-strain intraplate setting. Graphical Abstract