Sound Source Verification
Sound Source Verification (SSV) is intended to verify modeled predictions of how anthropogenic sound, including that produced by seismic survey sources, propagates in the environment. Regulatory agencies are increasingly requiring SSV measurements as a condition of exploration access licensing to enable them to acquire complete sound field maps during actual surveys. While SSV may contribute to better understanding model assumptions, it should not be imposed on exploration activities as a means of mitigation.
Because of the constantly changing conditions of the water column, SSV results are likely to be highly inconsistent and therefore are not reliable. And, in areas such as the Gulf of Mexico where the environment is highly variable, SSV is particularly onerous.
The IAGC instead recommends that general SSV be conducted for an area of interest, rather than on a project-by-project basis. When conducting SSV, the IAGC recommends the following process:
- Use a typical source array in representative habitats (e.g. shallow, shelf, and deep).
- Conduct sensitivity analyses on these profiles to determine the influence of seasonal variability.
- Collect empirical data on a number of representative projects (rather than all projects) to verify that the empirical data fall within the modeled range.
The IAGC does not support project-specific SSV because it poses a complicated and unnecessary burden on operations. As described above, generic sound source studies for representative habitats are more efficient, useful and verifiable when coupled with field studies rather than survey-specific SSV requirements.
The IAGC is committed to ensuring environmentally responsible and sustainable operations. More than five decades of extensive geophysical survey activity and associated research demonstrate that direct risk of physical injury to marine life is extremely low, with no evidence suggesting the sound produces biologically meaningful negative impacts on marine mammals.