THE ACOUSTIC FIELD OF MARINE SEISMIC AIRGUNS AND THEIR POTENTIAL IMPACT ON MARINE ANIMALS

摘要

The current quality of modelling of marine airgun sources is generally excellent and is within experimental error on the wide range of experimental data now available. At higher frequencies, although there is currently only one dataset out to 25kHz, agreement with the experimental data with a conventionally calibrated airgun model is again excellent in terms of defining the background level at high frequencies. The effect on marine animals remains difficult to quantify. An analogy of a human diver is presented here suggesting that pain would be felt with a typical array with a range of approximately 75m and that echo-location equipment operating at 20kHz would be effective up to approximately a range of 20m. This is compared as well as it can be with a commonly used threshold value in environmental monitoring but until more experiments are forthcoming in the marine biology community, such comparisons remain vague at best.