The Modeling and Simulation of Underwater Acoustic Energy Exposure Due to Near Surface Explosions on Marine Mammals

This paper discusses the development of a simulation tool for predicting the biological consequences from exposure to underwater explosions. During naval live fire exercises shock waves and intense acoustic energy are released into the surrounding underwater environment. A simulation tool is developed to predict the biological exposure effects from multiple transient acoustic events over a period of time. For this case, an underwater explosion model is coupled with simulation of marine mammal movements in 3-D to record acoustic exposure. Inputs to the simulation include the acoustic environment, marine mammal distribution and movement including behavioral response if appropriate, number of explosions, and source time line with locations that can be randomized if desired. Model outputs include positive impulse, peak pressures, and acoustic energy exposures. Shock wave impacts are assessed using the modified Goertner Impulse Criteria Goertner 1982, peak pressure exposure and hearing hazard predicted using energy flux density exposure verses time Goertner and Lehto 1996. This simulation can be used as a predictive tool by environmental planners to reduce or eliminate undesirable effects on the environment from multiple detonations. Results are shown for a hypothetical test scenario.