Thursday, September 18, 2014

Seismic gear is deployed, and we are collecting data!

Yesterday, we deployed the seismic streamer and source of the R/V Langseth in record time - its no small feat to put 8 km (~5 miles) of streamer plus other equipment in the water behind a ship.  The streamer is filled with pressure sensors that will record sound waves that have traveled into the earth and bounced off geological features, like faults, sedimentary layers, and ancient lava flows.  It is unwound from a gigantic spool on the back of the vessel.  As it leaves the ship, we festoon it with a variety of important devices, like “birds” that control the depth of the streamer, “streamer recovery devices” that are air bags that deploy and float the streamer to the surface if it gets too deep, and acoustic navigation units that are used to help determine the position of the streamer beneath the ocean surface.  A tail buoy is located at the end of the streamer to help with positioning and alert others of the presence of the streamer, and a float is at the front to further control the depth of the streamer. We also check that everything is working while we’re putting it into the water. We deployed all 8 km in just 7 hours, and were rewarded with a rainbow and spectacular sunset as the last bits of equipment went off the stern.   We also deployed the seismic source, which consists of air guns suspended below four snake-like black floats.  Now that all the kit is in the water, we are happily collecting data. Its a very good moment when the seismic data begins to come in...

Donna Shillington aboard the R/V Langseth
The top of the streamer reels. We are unspooling seismic streamer from the reel on the right. (Photo: Jenna Hill)
Looking towards the stern across the streamer reel (Photo: Derek Sawyer)
Matt, Sasha and Carlos attach a bird to the streamer
The streamer entering the water behind the ship with a bird
Kara fetches a bird to place on the streamer
Matt and Robert monitor the deployment operation from the main lab.
A rainbow hovers over Jenna and Ben with the final bit of streamer (Photo: Derek Sawyer)

No comments:

Post a Comment