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How does the Seabeam system map a wide swath of seafloor beneath a ship?

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The Seabeam system is a sophisticated multibeam echo sounder used to map the seafloor by producing a two-dimensional, or "swath," description of the ocean bottom from a single ship.12

It operates on the fundamental principle of acoustic ranging: the depth of the seafloor is determined by measuring the elapsed time between the transmission of an acoustic pulse and the detection of its echo. By multiplying one-half of this elapsed time by the speed of sound in seawater—approximately 1,500 metres per second—the system calculates the precise distance to the seafloor.1

Unlike traditional single-beam sounders, Seabeam utilizes multiple acoustic beams to survey a wide area simultaneously as the vessel moves. These acoustic pulses are typically generated by piezoelectric transducers. By processing these multiple returns, the system allows researchers to map the morphology and topography of the seafloor with high accuracy, providing a comprehensive view of features such as mountains, plains, and canyons.12