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How does seismic reflection reveal rock layers beneath the seafloor?

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Seismic reflection is a primary method for mapping the structure of the Earth's crust beneath the seafloor. The process functions similarly to echo sounding, using acoustic signals to probe subsurface layers.12

The technique involves the following steps:

Generating Waves: A sound source, such as an air gun, triggers seismic waves that travel downward through the water and into the sub-seafloor strata.234
Reflection: When these waves encounter interfaces where rock properties—such as density—change, a portion of the energy is reflected back toward the surface.14
Detection: Towed hydrophone arrays (streamers) detect these returning sound waves.3
Analysis: By recording the elapsed travel time and the strength of the returning signals, scientists can calculate the distance to these interfaces.13

By mapping these reflections across many locations, researchers can determine the relief of rock layers and create detailed cross-sectional profiles of the subsurface. Advanced 3D processing allows these data to be visualized as a continuous cube, helping to identify complex geological features or deposits.143