The swell is still high when Jason returns to the surface making recovery a challenge, but soon he is safely onboard and tied down. The scientists and grad students rush in with buckets and baggies and soon the lab is a flurry of activity. The smell was noticeable even before we got into the lab. Sulfur compounds make themselves known with their typical perfume of rotten eggs. Tony B. used a Geiger counter to check for radioactivity. So little is known about the mud, rocks and life forms from the deep sea that the scientists are very careful in handling the materials. Bacterial mats covered much of the chimney surfaces so everyone washes their hands thoroughly after handling any of the specimens.

Everyone was anxious to get a long core sample from this obviously active flow area. Our piston core target was the chimney field. I mentioned previously that by using GPS, transponders and the ship’s dynamic positioning, we can aim for precise locations. Still, we were quite surprised when we hit the chimney field right on target. We would have preferred a bit of a miss. The trigger core came back with chimney fragments but the piston core hit rock, bounced off the surface and returned with a few inches of black rock. Our core master was not pleased with the resulting destruction of the core cutter. This is the same piece of equipment that exploded off the end of the pipe and sank after a core sample on day 10. Also, the metal “fingers” that hold the mud in the pipe were turned inside-out. I wonder how many core cutters Chris M. brought on this trip.

We mapped through the night as we headed back to Big Blue Seamount. Transponders were put in place but it was too rough to launch Jason so we mapped through the day. We took a piston core at a small seamount north of Big Blue, laughingly referred to by Nathan as Baby Blue. I have what they tell me is a “very important job” during the piston coring. All I do is hold a line—a very important line? But the sunset was superb and I still like being a part of it all. Baby Blue was named correctly and gave up a 6 foot sample of sediment and blue mud.

The seas are calm and Jason is launched at 2030. What new mysteries await discovery?

Science Summary - Day 24, April 15th

Science Objectives, Day 24:

The twenty-fourth day of the cruise, Apr. 15, we will leave transponders on Quaker Seamount in hopes that we may be able to return and further explore along the eastern summit fault traces, where active chimneys are forming and where a piston core brought back a short interval of sulfide precipitate (and a badly mangled core cutter!) beneath a couple of centimeters of sediment and the trigger core recovered white chimney material (including one small clam shell). The chimney fields on Quaker are unlike any previously seen on any dives on the Mariana forearc serpentinite seamounts. We intend to move to Big Blue Seamount and set transponders at the summit in hopes of an opportunity to launch Jason2/Medea once the seas settle further. They are predicted to do so around noon and we anticipate a launch soon after that. If weather conditions worsen, we will core using the break-away corer, a special coring device designed by the chief scientist and the coring technicians at Oregon State University especially for use on these seamounts. The break-away corer is one that permits the metal core barrel to be separated from the weight stand and upper part of the core barrel upon impact. The inner core liner is attached to the upper part of the core barrel and after the core penetrates the sediment the weight stand, upper core barrel, and inner core liner are recovered, leaving the outer core barrel behind in the sediment. This, in essence, creates a mini-cased hole in the sediment. The intent is to return to the core site in the future, insert instrumentation into the barrel, and seal it off with a cap that is yet to be designed. The break-away core barrel was improved upon in the early part of our cruise by C. Moser and C. G. Wheat who drilled holes in the lower part of the metal core barrel making perforations, which should permit greater flow of formation fluids into the barrel. This break-away core will be navigated within the transponder net so that we can return to it with the ROV and observe any activity associated with escape of formation fluid or gas. We anticipate gas may be emanating from the seafloor at the site because of its presumed presence in the first core recovered from Big Blue Seamount’s summit. The core cutter for that core shot 10 feet off the end of the core barrel and fell back into sea.