Abstract
Buitengaats C.V. (Gemini) conducted pile driving works for the Offshore Wind Farm (OWF) Gemini in the Northern Sea (Dutch area). According to the permit, one of the requirements for the construction and operation of the wind farm Gemini is the conduction of a monitoring and evaluation program (MEP). One part of this MEP is the measurement of underwater noise during piling and of ambient noise before or after piling. In accordance with the requirements, underwater noise during pile driving was measured at two different Monopiles (foundation structure of the wind turbines) and one Pin-pile (jacket foundation of the Offshore High Voltage Station), at four distances (MP1 to MP4 at 750 m to approx. 60 km) to the source. The technical differences between the piles are listed in Table 1. The aim of the measurements during pile driving was to evaluate the influence of distance to the piling source on the underwater noise. Furthermore, a comparison between the underwater noises of the different pile designs was conducted. Additionally, the ambient noise before and after piling was measured. The obtained data will be used for the validation of the TNO models (Aquarius and Zampoli). This validation is outside the scope of this report. Scope of this report are the detailed documentation of the conducted underwater noise measurements and the presentations of the results.