Acquisition ON

At this point we are approximately 130 miles southeast of the coast of Kodiak Island, Alaska, and are heading southwest. We successfully deployed the seismic streamer early in the morning yesterday, and started acquiring seismic data a few hours later. The streamer has recording devices (hydrophones) built into it, is 4 km long, and is pulled behind the ship. We also have four cables with seismic sources that are pulled behind the ship. Our ship speed is around 4.5 knots, which is intentionally slow to keep the strain on the cables from getting too high. We have had onboard lectures every day, starting with an introduction to the AACSE project and our science goals, and now moving on to the
nitty-gritty of seismic processing. We have several computer workstations set up and students will start processing our brand new seismic data tomorrow.

IMG_2425_SafetySuit-lo.jpgWill Frazer (Binghamton) (in Gumby suit) and Tom Spoto (LDEO) (with orange tshirt) demonstrate the use of a safety suit (immersion suit) (also called a Gumby suit for obvious reasons). Ocean temperatures in this area are around 48 degrees F, so learning how to use an immersion suit for possible ship emergency is essential.

IMG_3477_brandon_work_vest-lo2
Brandon VanderBeek (Univ Padua) (foreground), Mitchell Spangler (Indiana Univ), and Ellyn Huggins (Univ Nevada Reno) on the deck of the R/V Langseth. Safety vests (life jackets) are required for any work outside on the deck of the ship.

IMG_3491_Alan_instructions2-lo.jpg
Alan Thompson (LDEO) gives instructions on how to attach ‘birds’ to the seismic cable (the streamer). The streamer is an enormous yellow cable (4 km long) that has acoustic listening devices (hydrophones) buit into it. The streamer is pulled behind the ship and records reflections generated by the acoustic seismic source array.Twelve ‘birds’ are attached to the seismic streamer and are used to control the depth of the streamer, and relay information back to the ship about the position of the streamer. From left: Brandon VanderBeek (Univ Padua), Tom Norris (Biowaves), Hongda Wang (Univ Colorado), Carlos Gomez (Cal State Northridge), Ellyn Huggins (Univ Nevada Reno), Alan Thompson(LDEO).

IMG_3539-LuciaHongda-Bird2-loLucia Gonzalez (UTEP) and Hongda Wang (Univ Colorado) attach a seismic cable control bird to the streamer.

IMG_3525_EllynMitchell-Bird4-loEllyn Huggins (Univ Nevada Reno) and Michell Spangler (Indiana Univ) carefully lower a seismic cable control bird over the side of the ship. Care must be taken to avoid banging the wings of the bird against the side of the ship, which can break the wing.

Anne Sheehan
University of Colorado Boulder

Photo Credits:
1st photo: Anne Sheehan
All other photos: Anne Becel

 

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