Dive and Discover : Daily Updates

Alvin rolled out of the hangar this morning for its last dive of this cruise under a brooding sky with dark clouds. Although we saw our first rainfall last night, it was definitely not going to be our last! We would see light to moderate rain falling throughout the day. Along with this inclement weather also came an increase in the sea state and wind, up to 22 knots! The crew of the Alvin and the Atlantis showed off their skill, though, as they launched the submersible just as efficiently as they do every day. Alvin, with pilot Pat Hickey and observers Dan Stuermer and Louis Cabot, headed back to the hydrothermal vent fields of the Bio-Geo Transect at 9 degrees 50’ N to take water samples, sulfide and biological samples for genetic studies, take digital photographs, and make observations.

Before the dive, the plywood painting of Dave Olds was given the finishing touches and mounted on Alvin’s basket for the ride down to the seafloor. Dave’s plywood image will keep some hydrothermal vents and animals company, and will remind all future visitors of the great contributions he has made to the Alvin program and helping scientists get their data from the seafloor.

The end of a cruise usually marks a time when cruise T-shirts are designed and made. The crew and science party were excited as the news about the cruise logo and T-shirt design that Paul Oberlander had made spread around the ship. Paul started making T-shirts with his design for each person on the ship. Check out the image below for a sneak preview of the logo for cruise #2 - you may get to see it before some of people on the Atlantis do!

The Towed Camera Sled rose from the deep again this morning at 0215 hours. The Night Owl Crew washed it down, started downloading pictures and then went to bed to try to return to a daytime schedule. After they got up around lunchtime, they started taking the sled apart and storing all of the components so they can be used again in the future. Margo, Greg, Del, and Jenny are all thrilled - the Sled collected over 13, 000 high-resolution images of the ocean floor during the eight camera tows.

The Alvin crew also had a slightly different recovery procedure today, too. Immediately after Alvin was pulled up from the choppy seas and set down on the deck at 1345 hours, the crew began to remove the outer panels, or “skins” as they call them, and scrub it down thoroughly with soapy fresh water in order to rinse off all the saltwater. Saltwater is extremely damaging to all of the metal pieces and parts of the mechanical and electrical systems on the sub and can’t be left on any of the equipment.

Whenever the sub is not diving for an extended period of time, like the next 6 weeks when it and Atlantis will be in San Diego, California for routine maintenance, the sub is thoroughly washed and all the systems are checked. A routine battery servicing is also scheduled so the next group of scientists gets as much time as possible on the seafloor to do their science. On this cruise we got an average of better than 5 hours of bottom time and traveled over 7 kilometers on nearly every dive.

As the work on the back deck was completed, and Alvin was snug in its hanger, the ship began steaming north-northeast towards Manzanillo, Mexico. The engineers were watching the one working thruster carefully and were pleased that the ship was making about 9 knots even in the moderate seas.

Dive Summary
On Bottom: 0930 hours
Off Bottom: 1215 hours
Maximum Depth: 2510 meters

The dive provided an opportunity to collect some hydrothermal fluid samples using the gas-tight bottles from the Bio9 vent area. It turns out that these two vents have been growing and falling over with some regularity. Bio9 Prime vent has toppled over again, and it appears that the HOBO temperature logger that was deployed in the vent last May is lost. Hopefully, the next Alvin cruise that will come back to this site in April can track it down. Pat sampled a vent only a few meters away from Bio9 Prime with the gas-tight bottle and got a good sample of 381°C fluid. He must have gotten pretty close to the hot stuff because we noticed that the starboard (right) side of one of the sub's rear panels was burned a little by a black smoker! The next vent Pat sampled is close to Bio9 Prime vent and is the same one that Dave Olds’ plywood painting is leaning up against. At this vent, Pat also took a sample of an active sulfide chimney with Alvinellid worms on it for some geochemical and genetic analysis by Prof. Rachel Haymon at the University of California-Santa Barbara.

The dive then traversed the seafloor down the middle of the Bio-Geo Transect and took video images of the volcanic flows and hydrothermal vents. They ended the dive near TY vent where they collected a lava pillar and mussels that were growing near the margin of the axial trough. The mussels included all sizes from big ones that are over 8 centimeters long to little babies that are only about 50 millimeters long. Dan Fornari had lots of work to do after the samples came up to prepare them for the different biologists, geochemists and geologists who would be using them for their research.

The two observers on today’s dive were both novices, so naturally they had some wet surprises waiting for them when they climbed out of Alvin and greeted people on the fantail. Lou got a ritual hosing down by the Alvin crew and Greg Kurras. Dan Stuermer had the honor of having several buckets of iced seawater poured over him. Both Lou and Dan were happy to get inducted into the deep sea divers club! They had a terrific experience and collected some great samples.