August 15, 2006 Options

[Steve_Stevenoski]

August 15, 2006

12:30 a.m. and the cage is in the water. If things go to plan we will have the cage in the water for the next two days as we collect refraction data along the Mendeleev Ridge. Fourteen instruments are positioned on a line about 80 miles long. The instruments are about six miles apart, but the wind is blowing at 20 mph or more and the ice floes that the instruments are on have drifted over a mile since deployment for most of the instruments. This will make it more difficult to predict the location of the instruments over the next two days. We need to know the approximate positions of the instruments so that waypoints can be given to the bridge so that the course that we take runs roughly parallel to the line of drifting instruments.

Snow on Towing Lines


We are 40 minutes into the seismic line and a seal is seen within a quarter of a mile of the ship track. The Marine Mammal Observer protocol requires us to stop using the air guns when a marine mammal is with a quarter mile radius of the ship. The ship continues to head to the waypoint, 15 minutes later, the seal is out of the contact radius and we slowly bring up the air guns one at a time. We continue until 4:00 when stop for the scheduled cage checkup.

We knew that we have some air hoses to tighten, but as we lift the cage we find that the number 5 air gun is hanging from the security cable. The Bolts attaching the gun to the cage have been sheared. If the cable had not been installed, the gun would have broken free from the cage and ended up on the bottom of the Arctic Ocean.

Snowman


By 7:00, all repairs have been made and the cage is redeployed. Four ours later the cage was n deck, this time with two leaky hoses and two broken restrainer cables. We were back in business with gulls following the ship by 1:20. Outside of the occasional seal or polar bear in the distance, this was the first real sign of life that I had seen in weeks.

We continued until dinner when we pulled the cage for some major repairs. Larry Phillips identified a couple of sites of interest for coring. We continued to investigate the areas in proximity to the pockmarks. Mark H had been in correspondence with one of his colleagues with a background in marine biology. He and a number of the other scientists were doing a survey of the different types of organisms that were in the upper portion of the "pockmark" cores. They were trying to quantify the diversity of mollusks and other organisms that were present. In addition they were looking for organism that were still alive following the 1000-meter plus assent from the seafloor.

Marcy Evaluates Core Samples


While coring was taking place, Anatoly went out on a helicopter flight to find and replace the radio in one of the seismic instruments. It took about an hour and a half for the entire trip. We were done coring by 10:30.

After the cores were taken, Harm gave instructions to the bridge to head to a number of specific waypoints so that they could use the multibeam and the Knudsen to map an interesting feature that was partially mapped in the transit to the coring station. For three hours we surveyed this new feature to get more detailed information from the bathymetry and seafloor structure in this area.