Britannica Sources used in this answer

How does side-scan sonar reveal the texture of the seafloor?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Hear Sylvia Earle talk about her life, work, and challenges as an American oceanographer and explorer — undersea exploration Learn about the pioneering life and work of American oceanographer and explorer Sylvia Earle.

Side-scan sonar reveals the texture of the seafloor by utilizing very high-frequency acoustic pulses, typically 100 kHz or higher.1

These systems operate as a form of active sonar, where piezoelectric transducers generate sound waves that are directed toward the ocean bottom. By scanning the seafloor to the side of a ship's track, the system analyzes the intensity of the reflected acoustic signals. Variations in the seafloor's roughness and composition cause different levels of sound reflection, which the sonar apparatus processes to create detailed images of the bottom's texture.1234

For even greater precision, near-bottom systems like the Deep Tow package are towed close to the seafloor—typically 10 to 100 metres above it—to resolve finer-scale features that are not detectable by surface-mounted equipment.1