Observed correlations between the sediment grain size and the high-frequency backscattering strength

Area of Science:

• Marine Geophysics
• Acoustic Remote Sensing

Background:

• Seabed characterization is crucial for marine operations and ecological studies.
• Acoustic methods offer non-invasive techniques for seabed surveys.

Purpose of the Study:

• To investigate the relationship between acoustic backscattering strength and sediment grain size.
• To assess the potential for seabed classification using multibeam echosounder data.

Main Methods:

• Conducted multibeam echosounder surveys at ten sites in Sequim Bay, Washington.
• Collected diver core samples to determine mean grain size.
• Calculated backscattering strength at frequencies of 200–350 kHz for various grazing angles.

Main Results:

• A significant correlation was observed between backscattering strength and normalized grain size at a 45° grazing angle.
• This correlation aligns with previously published findings.
• The results indicate a potential for simple seabed classification based on acoustic data.

Conclusions:

• Multibeam echosounder data can be effectively used to infer seabed sediment properties.
• The established correlation supports the use of acoustic backscattering for seabed classification in shallow marine environments.