Temporal variability of high-frequency seafloor scattering strength at a sandy site in the Gulf of Maine.

The goal of this research was to quantify the variability of seafloor backscattering strength occurring on time scales of weeks to months. Acoustic data were acquired using a 2-m-tall stationary mooring placed on the seafloor in a shallow water, sandy site located at the mouth of the Piscataqua River, New Hampshire, USA. Seafloor backscattering was measured at three frequencies (70, 200 and 333 kHz) and at low grazing angles (11° to 20°). Results show that scattering strength at fixed grazing angles varied weekly up to 10 dB and up to 18.8 dB over the 8-month deployment.