Technischer Bericht NTB 84-17

Bestimmung von rezenten Bewegungen der Erdkruste mit geodätischen Methoden

In the course of neotectonic investigations by Nagra (National Cooperative for the Storage of Radioactive Waste), the Federal Office of Topography conducted an intensive analysis of the levellings in the area of northern Switzerland. All 280 bench marks used in the first (1906 – 1930) as well as in the second national levelling net (1949 – 1982) were visited and geologically evaluated. Mean vertical movements for the last 40 – 70 years could be determined from the 190 most reliable bench marks. Relative to a group of bench marks anchored in gneiss in Laufenburg, a subsidence in the order of 0.2 – 0.3 mm/year can be shown for the area between Schwaderloch and Rekingen and an uplift of 0.1 – 0.3 mm/year for the area between Wildegg and Baden. These movements are most probably significant. The probability that there are relative height changes between these two zones is even greater. Only isolated movements can be found in the other areas.