In May 2006 the Christian Albrechts University carried out a boomer seismic survey in an area of 2 x 2 km² around the site with a 50 m gap between the tracks. In addition two OBSs [=Open Bottom Seismometers] and Scholte waves were used.
The seismology shows a plateau for the first horizon about 2 m below the seabed on the south-east side of the measured area. When evaluating the second horizon another raised site in the south-east was discovered.
It could be assumed from this, that because of the higher position of the horizons here an older and hence firmer and possibly more homogenous layer would be encountered. This assumption was supported by the clearly low penetration depths of the seismic sound waves into the ground here, as low penetration depths are an indication of firmer sedimentary compaction. In the valleys of the horizon one can anticipate softer stratifications having formed above this.
The artefacts (presumably stones), which were also imaged when the second horizon was evaluated, accumulate in the deep areas. To reduce the risks of cratering or of driving failure caused by stones, the position was placed as far as possible into this area.
The land survey for FINO3 is based on a site investigation with CPTU [=cone penetration test unit] pressure sounding in accordance with DIN 4094 carried out in October 2006 by IGB, Keller Grundbau, BLM-Storkow and HochTief with pressure sounding up to the capacity of the device, ram core drilling with continuing extraction of cored soil samples in accordance with DIN 4021 (35 m total depth) and geophysical borehole measurements with sonic-log, gamma-ray, gamma-gamma-log, induction- and neutron-log in PVC tubing.
According to the tests, the site consists of medium-dense to very dense sand deposits with partial gravelly and silty constituents.