In all weathers: LIAG researchers complete their largest 3D seismic survey to date
In spring, the LIAG research team acquired two seismic 2D profiles south of Klein Hollenbeck. Vibroseis trucks operated by the LIAG set the subsurface in motion using a baseplate coupled to the ground. Geophones placed along the tracks recorded the signals of the emitted elastic waves, which are reflected at different rock layers in the subsurface depending on the local geology.
From October to November, the team then carried out 3D seismics over a period of just over four weeks. North of Hollenbeck, they surveyed an area of around 300,000 m². A dense grid of receivers for the seismic waves and the application of different vibration techniques – compressional-wave and shear-wave seismics – were designed to achieve high-resolution imaging down to depths of around 600 metres.
“We are very excited to see the results,” says Prof Dr Gerald Gabriel, Head of Geophysical Exploration at the LIAG, who is scientifically responsible for the GeoMetEr project. “It was the largest 3D survey our institute has carried out with its own staff to date. At the same time, it was also one that involved particularly challenging conditions: in some cases, heavy rainfall made it more difficult to achieve good coupling between our seismic sources and the ground, as well as an efficient distribution of the source energy in the subsurface. Nonetheless, we are hopeful that the data quality will be good.” Collaboration with the owners and tenants of the areas used was excellent.
How will the project continue?
In October, airborne magnetic and electromagnetic measurements carried out by the project partners using a helicopter survey added conductivity information to the data base. All data sets are now being processed and analysed. In spring 2026, further drone-based measurements are planned, which will again provide very high-resolution coverage on a smaller scale to complement the helicopter data. A further seismic survey along a few selected profiles may also follow. The research team will then integrate all results in a complex evaluation workflow to create a consistent 3D model of the overburden above the Harsefeld salt structure. A research borehole is also planned to verify the results.
“Bringing together data from different geophysical methods makes the evaluation highly complex,” Gabriel explains. “But only then do we obtain an image of the subsurface that can more precisely reveal the key properties of the rocks and thus their suitability for specific utilisation potentials.”
Background information
The LIAG Institute for Applied Geophysics is an independent research institution based in Hanover. Together with TU Bergakademie Freiberg, it leads the GeoMetEr research project. Other partner organisations are the University of Münster, Leibniz IPHT, DMT GmbH & Co. KG, Terratec geophysical services GmbH & Co. KG, Supracon AG, Solexperts AG and the Federal Institute for Geosciences and Natural Resources (BGR). The research is funded by the Federal Company for Radioactive Waste Disposal (BGE): Harsefeld is one of two research regions used to develop methods for improved imaging of the overburden above a host rock – in this case, the Harsefeld salt structure as an example. The joint municipality of Harsefeld has already been ruled out as a potential site in the repository siting process; the work serves research purposes only.
Further information: www.liag-institut.de/geometer
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