The overall Cenozoic tectonic evolution of Northern Switzerland is an important driver for erosion, while seismicity and faulting are important factors that may affect long-term barrier performance. With respect to the assessment of future tectonic evolution, it can be concluded that:
The neotectonic setting of Northern Switzerland is influenced by the effects of the ongoing Alpine orogeny in the south, transtensional deformation within the Upper Rhine Graben and the Hegau – Bodensee Graben, and tectonic activity of the Jura Fold-and-Thrust Belt. This setting defines the boundary conditions for erosion processes (low uplift rates and baselevel drop).
The main neotectonic influence on the incision of the Hochrhein are low rates of North Alpine Foreland rock uplift, compared with low, potentially episodic subsidence within the Upper Rhine Graben. The longitudinal Rhine River profile is also influenced by continuous uplift of the Rhenish Massif and Eifel areas. Accordingly, the Hochrhein is presently buffered against fluvial processes approximately downstream of the city of Bingen.
Uplift rates in Northern Switzerland are generally low and in sub-mm/yr, ranging between 0.1 and 0.5 mm/yr, with strong dependency on the time interval. Average long-term uplift rates are < 0.3 mm/yr.
The trend of rock uplift reveals northward-decreasing rates perpendicular to the Alpine front. Thus, rock uplift is predominantly an Alpine signal, irrespective of the cause (tectonic vs. isostatic compensation).
Northern Switzerland is a low-strain domain; Horizontal velocities show a slight decrease in their north component towards the north corresponding to the inferred strain rate (~ 1 – 3 m/Myr/km). Tectonic deformation rates are currently low and comparable to the past (Section 4.3), which increases confidence in their extrapolation.
Seismicity in Northern Switzerland is sparse and generally at a low level compared to, for instance, the Upper Rhine Graben.
Inherited faults have acted as zones of weakness that preferentially localise strain. It is anticipated that this will continue in the future and deformation will focus along the regional fault zones rather than forming new faults between these zones.