Characterization of particle motion near offshore wind farm sites in the United States east coast

This study analyzes the particle motion data recorded on geophones and ocean bottom seismometers (OBXs) at various shallow water (water depth ∼30 m) locations in the U.S. east coast near offshore wind farms. The Block Island, Rhode Island site was the location of the first offshore wind farm in the United States. Data were collected at this site during three different deployments in 2015, 2016, and 2017. Particle motion measurements were made during construction and operation of the wind turbines during these deployments. Data collected on a 3-axis geophone will be discussed in this study. This sensor package included a 3-axis geophone and a co-located hydrophone. This 3-axis geophone measured the particle motion (particle velocity) in three mutually perpendicular directions along with acoustic pressure. The same sensor package was also deployed ten miles east of Ocean City, Maryland and near the Virginia wind farm. During this deployment, in addition to the geophone package, four Ocean Bottom Recorders (OBXs) were also deployed as a line array to record construction noise. Data from these deployments will be presented and compared with published data from other windfarm sites. [Work supported by the U.S. Department of the Interior, Bureau of Ocean Energy Management (BOEM), Environmental Studies Program]