The area to be surveyed extends from Kaiserstuhl, Hohentengen and Hüntwangen in the north to Neerach and Bülach in the south. The campaign, which will cover a total of 91 square kilometres, will start in the area around Kaiserstuhl; measurements will also be carried out in the neighbouring region of Hohentengen in Germany. As the River Rhine functions as a natural boundary between these two areas, the 3D seismic survey will be carried out in two blocks, starting with the northern section which lies mainly in Germany. These measurements are expected to take around 4 weeks. The Swiss section south of the Rhine will then be investigated
The German company DMT has been contracted to carry out the measurements on behalf of Nagra. Work in the field will be carried out from Monday to Saturday, with a short break between Christmas and New Year.
The 3D measurements will provide more detailed information on the subsurface geological environment. “The aim of the campaign is to obtain a comprehensive image of the rock layers beneath the surface”, explained Marian Hertrich, project manager of the 3D seismic survey, during today’s media orientation event in Kaiserstuhl. The principle of seismic measurements is similar to echo sounding on ships, using weak seismic waves generated at the surface to image deep rock layers. In the case of Nördlich Lägern, the target horizon for the measurements is at a depth between around 300 and 900 metres. This is the depth range in which a repository could be constructed.
“The investigations are being carried out with the agreement of the responsible cantonal authorities and begin only after the affected communities have been informed”, said Markus Fritschi, a member of Nagra’s Executive Board. All affected landowners and tenants are also informed in advance of the field work. “It goes without saying that all the workers involved in carrying out the measurements are under an obligation to proceed carefully and considerately”, added Fritschi. Should there be any damage or inconvenience despite this, those affected are recommended to contact Nagra directly on the free hotline 0800 437 333.
More information (in German) on the seismic investigations in the Nördlich Lägern region can be found on Nagra’s blog at www.nagra-blog.ch.