Environmental impact of a set of marine compressed air source configurations – a comparative study

The interest in the environmental impact of marine seismic sources has steadily increased over recent years as the risk of potentially harming or disturbing marine life has been brought into stronger focus. Designing a seismic source setup that simultaneously fulfill geophysical requirements and minimize the environmental footprint is often required up front of a seismic survey, but is difficult to assess. While the geophysical requirements of a survey are depending on geology and survey objectives, the output of a given source configuration does not. We have assessed, through modelling of the seismic source and analytical homogeneous propagation modelling, the decrease in environmental impact of the most frequently considered mitigation measures as a non-survey dependent comparative study. We show that many of the most frequently used mitigation measures have limited effect while other measures, especially changing the source setup to consist of triggering individual source elements separated in time, will result in a relatively stronger decrease of the potential environmental impact. This quantitative assessment gives a platform for understanding and evaluating different mitigation measures to lower the environmental impact of the seismic source.