Effect of Temperature on the Acoustic Reflection Characteristics of Seafloor Surface Sediments

Because the sound speeds of seawater and seafloor sediment both increase with temperature, the influence of temperature on the bottom reflection characteristics of seafloor sediments needs to be investigated. Based on the calculation of the temperature-controlled experimental measurement data of typical seafloor surface sediment samples, the temperature-dependent acoustic characteristics, including acoustic impedance, acoustic impedance ratio between surface sediment and seawater, and reflection coefficient, were analyzed. The effective density fluid model was used to analyze and explain the reflection coefficient variation of surface sediments with temperature and predict the dispersion characteristics. Results show that the acoustic impedance of the seabed sediment increases with temperature, whereas the acoustic impedance ratio and acoustic reflection coefficient slightly decrease. The acoustic impedance, acoustic impedance ratio, and acoustic reflection coefficient of sandy, silty, and clayey sediments vary similarly with temperature variation. Moreover, the influence of temperature on these acoustic characteristics is independent of detection frequencies.