Calibrated marine sparker source amplitude decay versus offset offshore Santa Cruz, California

This two-vessel survey was designed to quantify the decay of sound emitted from the SIG ELP790 minisparker (powered at 700 joules) and from the Applied Acoustics Delta Sparker (powered at 1.0 and 2.4 kilojoules) as a function of distance during marine geophysical surveys. Seven transect sites were surveyed at five different water depths (25, 50, 100, 200, and 600 meters) to compare the effects of water depth on peak sound level. The source vessel (RVPS) towed the sparker sound source as well as a calibrated hydrophone (TC4034) to record the near-field outgoing signal along the transects. The receive vessel (RVSL) maintained a nearly stationary position at the midpoint of each transect and continuously recorded sound with a calibrated hydrophone (CR3101 or CR3102). at depths between 10 and 20 meters. This data release contains RVPS and RVSL vessel navigation, RVPS near-field SEG-Y data, RVSL receive SEG-Y data, and SEG-Y peak amplitude data.