Broadband calibration of the R/V Marcus G. Langseth four‐string seismic sources

Abstract

The R/V Marcus G. Langseth is the first 3‐D seismic vessel operated by the U.S. academic community. With up to a four‐string, 36‐element source and four 6‐km‐long solid state hydrophone arrays, this vessel promises significant new insights into Earth science processes. The potential impact of anthropogenic sound sources on marine life is an important topic to the marine seismic community. To ensure that operations fully comply with existing and future marine mammal permitting requirements, a calibration experiment was conducted in the Gulf of Mexico in 2007–2008. Results are presented from deep (∼1.6 km) and shallow (∼50 m) water sites, obtained using the full 36‐element (6600 cubic inches) seismic source. This array configuration will require the largest safety radii, and the deep and shallow sites provide two contrasting operational environments. Results show that safety radii and the offset between root‐mean‐square and sound exposure level measurements were highly dependent on water depth.