MGL1109 Chirp - US Extended Continental Shelf Project: Gulf of Alaska CHIRP High-Resolution Seismic Profile Data

The Knudsen 2620 acquired sub-bottom profiles continuously throughout the cruise. The Knudsen was operated in 3.5 kHz Chirp mode, emitting a 1.5 kHz to 5 kHz (3 kHz bandwidth centered on 3.5 kHz) pulse from transducers mounted in the pod beneath the hull. A record window of 200 meters and assumed sound velocity of 1500 m/s remained constant through the cruise. The resulting data records were 267 msec long, with a sample interval 0.16667 msec (6 kHz). The ping rate varied over the course of the cruise. For most of the first two weeks, the ping rate was approximately 5 seconds. On or about June 23, the ping rate was increased to approximately 2 seconds.