Dive and Discover : Daily Updates

The weather was beautiful today as RV Atlantis continued its transit on a course of 008° towards Manzanillo, Mexico at a speed of just over 9 knots. Captain Silva and Kevin Fisk, the Chief Engineer, are pleased that the one stern thruster is doing such a great job. We are also lucky to have good weather and very calm seas as we “head for the barn”, the term usually used by folks at sea to refer to the transit back to port. It’s kind of like cows heading back to the barn...

Although yesterday was our last dive of Cruise #2, there is still a lot of work to be done! Even though there is no new data being collected, there is still plenty of information that has been gathered over the past two weeks for the scientists to analyze and archive. Making careful notes and documenting all of the observations and types of data collected during the dives and the camera tows, including navigation and the information from the gravimeter, magnetometer and transponders, is important to our experiment. One of the keys to doing a good experiment is to keep good notes so that other people can understand what you did and reproduce your results if needed.

The crew of the Atlantis is charged with the task of keeping everything running smoothly, from maintaining the engines in working order to navigating the ship towards our final destination. Outside they continued to fight the war against seawater by chipping off the rust and painting some of the metal surfaces of the ship. There were also fish to be caught, and lines were hung off the back of the ship in the hopes of hooking a big one! In fact, Patrick Hennessy had to change out the lines several times because some big fish had completely bitten off a few of the lures!

The Alvin crew continued their post-cruise maintenance of the sub as well as removing some of the sensors that had been used during this cruise, like the gravimeter, magnetometer and doppler sonar. The Towed Camera Sled also was stripped of its sensors and all of the equipment is being washed down with fresh water and the various O-rings, the rubber rings that make the water-tight seals in the pressure housing, cleaned and replaced as needed.

The scientists held a short debriefing in the library at 1600 hours. Dan Fornari spent time going over our new travel plans, as well as speaking very briefly about some of the preliminary results of the data gathered on the various Alvin dives and congratulating everyone on a job well done. Margo Edwards discussed some of the preliminary results of the Towed Camera Sled surveys and showed a map with the types of lava terrain plotted along the survey tracks. Tomorrow we’ll meet again to discuss the science that was accomplished on the cruise and the plans for more data analysis back on shore. Afterward, everyone headed back to the fantail for the traditional end-of-the-cruise photo -with one twist. Some of the party decided to go with an aquatic theme and jumped straight into the pool!

For dinner tonight we were treated to a special cook-out on the fantail! Everyone was able to mingle while we were eating our delicious meals cooked up by Jay, Jockie, and Ginger. After working so hard during the cruise, it is nice to be able to relax and talk with your new friends. Just as we were finishing dinner the sun was about to set. With almost no clouds in the sky, the sunset promised to be spectacular! Nearly everyone out on the fantail rushed over to the port (left) side of the ship to watch the sun go down on the horizon and hopefully catch a glimpse of the elusive “green flash”.

The “green flash” occurs in the instant that the sun sets over the horizon. The light from the sun is refracted, or ’bent’, by the atmosphere. All of the different colors contained in a beam of sunlight are bent a little bit differently, just like what happens to light when it passes through a prism, or why raindrops create a rainbow. The blue and violet ends of the light spectrum are scattered by all of the particles in the air, and water vapor gets rid of the yellow light, leaving mostly red and green.

Just as the sun sets on the horizon, there is sometimes a brief flash of green right in the same spot where the sun is setting. It is truly a rare event to observe. It lasts only a split-second! This phenomenon is best seen when there is a clear, cloudless, and open horizon, such as out at sea! Unfortunately, we did not see the green flash tonight, but we were still able to enjoy the gorgeous post-dinner sunset.

Tomorrow is the last day before we reach port and everyone will be busy packing up, cleaning the labs and their rooms, and getting ready to head home after a successful research cruise.