Particle motion observed during offshore wind turbine piling operation

Area of Science:

• Marine acoustics
• Environmental engineering
• Underwater noise pollution

Background:

• Offshore piling generates significant underwater noise.
• This noise can negatively impact marine ecosystems.
• Effective noise mitigation is crucial for environmental protection.

Purpose of the Study:

• To measure particle motion and noise levels from offshore piling.
• To evaluate the effectiveness of different noise mitigation techniques.
• To assess the impact of mitigation on noise characteristics.

Main Methods:

• Developed an autonomous, sensitive sensor (up to 2 kHz) for particle motion measurement.
• Conducted measurements for both unmitigated and mitigated offshore piling events.
• Analyzed acceleration zero-to-peak values and acceleration exposure levels.

Main Results:

• Mitigation techniques significantly reduced overall noise levels.
• Noise reduction was particularly effective at higher frequencies.
• A decrease in the power content of higher frequencies was observed.

Conclusions:

• The employed mitigation techniques are effective in reducing offshore piling noise.
• Reduced noise levels and high-frequency content lessen the potential impact range on marine species.
• This study validates the use of noise mitigation in offshore construction.