The joint project SIMULTAN − Sinkhole instability: integrated multi-scale monitoring and analysis − has the aim of developing and applying an early recognition system for the instability, unrest and collapse of sinkholes. The department is involved in this project with seismic and gravimetric methods.
Sinkholes − the most spectacular examples of which are sudden collapse holes in the surface of the Earth, with diameters of a few metres to several 100 metres − represent a serious risk for people and infrastructure, in urban areas in particular. The natural cause of sinkholes is the dissolution of soluble rocks (subrosion), and the associated creation of cavities and/or the destabilisation of the surrounding rock.
The aim of the joint project SIMULTAN is the characterisation and monitoring of sinkhole areas with geophysical, petrophysical and hydrogeological methods to develop an early recognition system for instability. The investigations are supported by scenario simulation and modelling. The focus regions of the SIMULTAN research project are Thüringen and Hamburg where sinkholes have already occurred in urban areas, or where subsidence has already been observed. LIAG is involved within two of the project's work packages: characterising critical zones using key geophysical parameters, and the geodetic-gravimetric monitoring of sinkhole regions.
High-resolution shear-wave reflection seismic (2D), vertical seismic profiling (VSP) with the stimulation of P-waves and S-waves, and well logging methods are used for structural investigation and the identification of geophysical parameters. The aim is to derive key physical parameters that describe the critical zones. In addition, repeated measurements determine the changes in the physical parameters over time.
Surface deformation is monitored by repeated levelling. A major challenge is to use repeated, high-precision, gravimetric measurements to detect potential mass changes in the rock formations, which induce the surface deformation in the first place, and to verify these mass changes by modelling the mass deficit.
Behörde für Stadtentwicklung und Umwelt Hamburg
Thüringer Landesanstalt für Umwelt und Geologie
Landesamt für Landwirtschaft, Umwelt und ländliche Räume Schleswig-Holstein