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Calibration of Ewing acoustic sources
Photos Courtesy of Nathalie Jaquet and Jonathan Gordon
As anthropogenic noise in the oceans increases we are becoming increasingly
aware of the possibility of its impact on marine mammals. As part of
Lamont-Doherty Earth Observatory and the National Science Foundation's commitment
to determining any possible impact on marine mammals from active source seismics,
we participated in SWSS (Sperm Whale Seismic Study) in the summer
of 2003. In addition, we made the first well-calibrated
broad-frequency measurements of the RV Ewing's acoustic sources to accurately
determine source levels at a range of frequency-of-concern to marine mammals
(1Hz - 25kHz). Until source levels are accurately constrained at a
range of frequencies it will be very difficult to predict, and therefore
prevent, the circumstances under which marine mammal disturbance might occur.
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