Long-range seismic sound measurements and modeling – what does it take to get it right?
B. Martin, L. Horwich, C. Morris, M.N. Matthews and K. Broker
Event name: 80th EAGE Conference & Exhibition 2018 Workshop Programme
Session: WS14: The Effect of Seismic Surveys on the Marine Environment
Publication date: 15 June 2018
Info: Extended abstract, PDF ( 812.87Kb )
Price: € 20
Increased interest in seismic survey’s possible disturbance of marine life and masking of biologically-relevant sounds means that the accuracy of acoustic propagation models at ranges well beyond auditory injury distances is important. The models are used to predict the effects of noise before a survey occurs as well as to model the noise exposure of tagged animals from actual surveys. The definition of long range depends on the animals of concern – it could be 5 km for porpoise, or 100 km for baleen whales. This abstract summarizes two projects where precise measurements of seismic airgun sounds were made over a wide range of distances from the source. We present typical data collected over ranges of .1-150 km, the frequency content as a function of range, and how the modeled levels compared to the measurements. For data collected in Baffin Bay, the model accuracy is highly dependent on the accuracy of the bathymetric data. For measurements at the edge of the Gran Banks, high resolution date-specific sound speed profiles are required to accurately model received sound levels.