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Seismic surveys are carried out in the investigation of subsea geological formations.

In the course of performing seismic surveys, high level, low frequency sounds are directed towards the seabed from near-surface sound sources that are towed by a vessel. Signals reflected from the geology below the sea floor are recorded by towed hydrophones. Analyses of the returned signals allow for interpretation of subsea geological formations. The seismic data is computer processed after being recorded by the hydrophone streamers.

During surveying, vessels travel at a speed of four to six knots. The sound source is situated some 300 m behind the vessel at a depth of three to 20 m below the surface. A seismic vessel would typically be active for two to eights weeks during each campaign.

Scientific studies and technical reviews indicate that the potential for harm to various benthic (bottom dwelling) organisms, fish and marine mammals from exposure to acoustic energy from seismic sources is very low and only occurs when the animals are in close proximity (arround two meters) to the seismic source.

diagram of the seismic survey process