Acoustic Pressure, Particle Motion, and Induced Ground Motion Signals from a Commercial Seismic Survey Array and Potential Implications for Environmental Monitoring

An experimental marine seismic source survey off the northwest Australian coast operated a 2600 cubic inch (41.6 l) airgun array, every 5.88 s, along six lines at northern site and eight southern site. The array was discharged 27,770 times with 128,313 pressure signals, 38,907 three-axis particle motion 17,832 ground signals recorded. Pressure were accurately measured horizontal ranges from 12 m. Particle saturated out to 1500 m range (50% of 230 590 sites, respectively). For unsaturated sound exposure levels (SEL) correlated measures level water acceleration (r2= 0.88 0.95 0.97 southern) 0.60 0.87, effective modelled 247 dB re 1µPa peak-to-peak, 231 1 µPa2 mean-square, 228 µPa2?m2 s SEL 15° below horizontal. Propagation loss ranged ?29 ?30log10 (range) ?38log10(range) site, for measures. These high propagation losses are due near-surface limestone in seabed North West Shelf.