E Source A New Future

Summary

Air-gun sources and their environmental impact have been debated for a long time. While some of this debate might be exaggerated it is generally accepted that the high frequencies outside the seismic bandwidth are of no benefit to imaging or subsequent attribute inversions although the upper boundary of the desired bandwidth can vary depending on region and target. The undesired high frequency part of air-gun outputs is mainly attributed to the air being released very fast and abruptly creating a steeply rising seismic pulse. In 2014 Coste et al. introduced an airgun design with the aim to attenuate the high frequency emissions of airguns by releasing its air in a carefully designed way such that the steepness of the rising edge can be controlled. Controlling the steepness acts like a physical low-pass filter and thus reduces possible effects on cetaceans and other marine mammals that are sensitive to seismic energy at higher frequencies.

Several studies have been carried of the last 2 years showing growing interest in this technology as environmental mitigation is becoming more central to survey planning.