Abstract
The Coastal Virginia Offshore Wind (CVOW) consists of two turbines roughly 40 km off the coast of Virginia Beach, Virginia. Water- and seabed-borne acoustic signals from impact pile driving at CVOW were recorded during the installation of these turbines in May 2020. In-water pressure signals were measured using two vertical line arrays (VLAs) at ranges of 3 km and 7.5 km. The water depth at the wind turbines and both VLAs was about 26 m. During installation, one of the piles utilized a double bubble curtain during construction while the other pile did not. Bubble curtains are used to reduce the acoustic impacts of pile driving by creating a barrier of bubbles around the source. We found that the bubble curtains were most effective at longer ranges and at frequencies above 200 Hz. Normal modes are an efficient representation of the acoustic field in this relatively range-independent shallow water environment. The amplitudes of acoustic modes at several frequencies were used to analyze the effectiveness of bubble curtains. Energy propagating in the seabed was also measured by an array of geophones and was found to be unattenuated by the bubble screens.