Open Session - SWISS GEOSCIENCE MEETINGs

12.28
Estimation of local tectonic movements using continuous GNSS network
Villiger Arturo*, Heller Oliver*, Geiger Alain *, Kahle Hans-Gert*, Brockmann Elmar**
*Geodesy and Geodynamics Lab, Institute of Geodesy and Photogrammetry, ETH Zürich (arturo.villiger@geod.baug.ethz.ch)
**Swisstopo
The objective of project TECVAL is to assess local crustal movements with modern geodetic techniques in an area north of
the Rhône valley extending from Martigny to Raron. Although the Valais is a region of relatively high seismic activity within
Switzerland, the deformation rates reveal small amounts only. Nevertheless, the main challenge is to detect these movements
by GPS at a high level of significance.
The stations for the evaluated network are part of the Automated GPS Network (AGNES), operated by Swisstopo, or built up
for this project and run by ETHZ. In order to determine movements relative to the Eurasian plate and to assess a new rotation
pole the network includes European stations from IGS and RGN. The relative time series are evaluated in a local topocentric
coordinate system. Due to the small tectonic velocities seasonal and other disturbing effects have to be taken into account.
To this end the time series have to be available for at least a few years. To determine the velocities from time series a
robust estimator has been used. This approach significantly reduces the influence of outliers. After the robust elimination
of outliers the final velocity is determined by a least square estimation.
In order to verify the achieved results in this area the uplift can be compared to a model calculated from levelling measurements.
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Symposium 12: Data acquisition, Geo-processing, GIS, digital mapping and 3D visualisation