Open Session - SWISS GEOSCIENCE MEETINGs

REFERENCES
Dimitriević, M.D., 1997. Geology of Yugoslavia., Geological Institute GEMINI Special Publication, Belgrade, pp. 187.
Pamic, J., 1993. Eoalpine to Neoalpine magmatic and metamorphic processes in the northwestern Vardar Zone, the
easternmost Periadriatic Zone and the southwestern Pannonian basin. Tectonophysics, 226(1-4): 503-518.
Schmid, S.M. et al., 2008. The Alpine-Carpathian-Dinaridic orogenic system: correlation and evolution of tectonic units.
Swiss Journal of Geosciences, 101(1): 139-183.
Ustaszewski, K. et al. 2007: The Late Cretaceous supra-subduction magmatism of North Kozara (northern Bosnia and
Herzegovina): Implications for the Cretaceous to Paleogene collisional history between Tisza and the Dinarides, EGU
General Assembly 2007, Volume 9: Geophysical Research Abstracts: Vienna, p. 03659.
1. 0
Recent vertical movements from precise levelling in Switzerland
Schlatter Andreas
Federal Office of Topography swisstopo, Geodesy, Seftigenstrasse 264, CH-3084 Wabern (Andreas.Schlatter@swisstopo.ch)
Repeated measurements to determine national heights have shown that the Alps are still rising with respect to the Central
Plateau. These so-called precise levelling lines follow major traffic arteries, pass through important tunnels and cross over
main alpine passes. These networks include approx. 8,000 benchmarks whose heights serve as the vertical reference for most
observations in Switzerland. The measurements used for this representation were first made between 1903 and 1945 and
have since been repeated at least once.
The reference point for the investigation of vertical movements was arbitrarily chosen in Aarburg (Canton of Aargau) at the
south foot of the Jura Mountains. All of the substantiated vertical changes are therefore relative uplifts or subsidences with
respect to this point. Approx. 220 benchmarks were selected for the illustration in fig.1. Most of them are anchored directly
in rock, some on buildings, which are known to be stable and well-founded.
The two maximum uplifts of up to 1.5 mm/year in the area between Sitten and Brig as well as in the Grisons (Chur/Engadin)
are striking. Observations in the Jura Mountains are more likely to show subsidences. The Central Plateau seems to stay more
or less stationary with the tendency of a tilt: subsidence in the west, uplift in the east. Even though the amounts seem small,
the Alps are growing up to 15 cm in 100 years. Had a Roman citizen started out in Aarburg 2000 years ago to make his way
to Rome across one of the passes in the Grisons, he would have had 3 meters less to climb. In geological terms the uplifts
reach a total of several kilometers, which are of course continuously being offset by erosion. There are probably two main
causes for these large-scale bulges:
1. The uplifts are a direct result of tectonic activities, in this case the penetration of the continental, European crust by the
Adriatic spur.
2. The uplifts are so-called isostatic equalization movements. The earth's crust floats on the denser material of the earth's
mantle. The erosion and also the melting of large ice masses at the end of the Ice Age result in delayed uplifts. This could be
compared to a boat which rises in the water as it is being unloaded.
REFERENCES
Schlatter, A., D. Schneider, A. Geiger and H.-G. Kahle 2005: Recent vertical movements from precise levelling in the vicinity
of the city of Basel, Switzerland. International Journal of Earth Sciences Vol. 94/2005: 507-514.
Schlatter A. 2007: Das neue Landeshöhennetz der Schweiz LHN95. Geodätisch-Geophysikalische Arbeiten in der Schweiz.
Schweizerische Geodätische Kommission Band 72.
61
Symposium 1: Structural Geology, Tectonics and Geodynamics