August 2, 2006 Options

[Steve_Stevenoski]

August 2, 2006

Coring went on throughout the night. As the ship transited to the next station they assembled the piston corer. This corer is capable of collecting a four-inch tube of seafloor sediments up to thirty feet long. Once the core was retrieved secured on deck and evaluated, they had a 29.5-foot core of blue clay sediments with the odor of hydrogen sulfide. Larry Phillips is the scientist in charge of the coring. He felt that after his preliminary evaluation that the sediments collected could be as much as 9 million years old.

Gun Controllers


Kelly and Larry had placed a sample of the mud on one of the lab benches with a sign, "don't touch, important mud. They were filtering the mud to remove the water, and allow the sample to dry. Later in the day they would inspect the samples under a microscope to look for the types of particles that make up the sediments and small fossils called foraminifera.

With the core was secure on deck, we started heading for instrument number one. We would transit to the start of the seismic instrument line deployed by the helicopters, evaluating the ice along the way. If the ice conditions were suitable, we would swing around instrument 1 and head back up the line triggering the guns to produce sound pulses that would be recorded by the 12 seismic instruments on the ice. The data collected from these instruments would then be used to produce seismic profile maps of the ocean crust as deep as the Earth's mantle.

We spent the morning tightening and fabricating and rebuilding the gun cage. Kevin and Matt took apart and reassembled one of the GI guns. We would have to do some welding and grinding, so Dale requested a hot permit from the OD. I worked on some shims and the holes for the gun mounts.

At 10:00 those of us working on the cage, headed back in to the main lab. The ship was at flight con 1. Anatoly was off on a flight to locate instrument number 7. The currents and wind are constantly repositioning the ice flows that the instruments are on. The scientists communicate with the instruments by radio when they are in range. Number seven has been out of range long enough that we are not quite sure where it had drifted. On the flight they would try and contact the instrument by radio. If that failed, they would try to locate it visually, land and replace the instrument with another.

Big Bertha Corer


Half way through lunch, Larry Lawver came into the mess to grab a bite to eat and told us that the ship had communicated with instrument number seven and that it was OK and was found just 3 tenths of a mile off the cruise track. Calculating the positions of the instruments due to drift is difficult and unpredictable.

All afternoon and evening we worked on getting the cage ready for a late evening/early morning deployment. The cables and hoses were disconnected and the tube was moved and attached to the center of the cage. The towing lines were reattached farther forward on the frame, and we added new longer tag lines. We felt that all of the adjustments that were made would improve the stability of the cage and security of the guns in the cage as we towed it though heavy ice. Steffen added release valves to the compressor hose connections to help vent air more rapidly in the event of an unexpected shutdown like we had experienced.

Steffen and Russell started up the compressors at 10:00 to have them warmed up and ready when we got the word to deploy.