Computer Modeling of Underwater Sound

Computer modeling of underwater sound propagation indicates that sound from airguns does not concentrate shoreward, where marine mammals, particularly seals, might congregate.

The model is for 50 Hz sound propagating in a water wedge over a mud bottom. In each of the three figures the seabottom is the faint line that rises to the right at the angle given in the right margin. The seabottom slopes down to the left, to where it attains a maximum depth of 200 m, then the bottom remains flat. The sound source is at the top of the red area (10 m deep and 2.5 km from the beach). Here sound levels are highest (red represents -40 dB and higher).

Streaks of color that slope down to the right show sound that exits the water layer. Purple near the "beach" indicates low sound levels (purple represents -110 dB and lower).

Modeled using "rams" software by M. Collins.