Marine Mammals and Low Frequency Active Sonar (LFAS)


Low Frequency Active Sonar (LFAS) is a military sonar technology designed to detect and track quiet submarines. The U.S. Navy is planning to deploy LFAS in 80% of the world’s oceans at an effective source level of 240 dB. Using the Navy’s number of 61.5 dB (to express the conversion between air and water) 240 dB is equivalent in air to being 20 feet away from a Saturn V rocket at takeoff. NATO and other navies also have LFAS and other high intensity sonars.


Major concerns about LFAS and Marine Mammals include:

(See Navy/NOAA Report


Prepared by Marsha L. Green, PhD – Ocean Mammal Institute

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