It is late on Saturday, we are soon heading back to port, and the city lights of Guaymas will tonight appear on the eastern horizon. The labs get very busy, not just with last-minute sample processing, but with packing up, cleaning, copying data, and getting our precious samples ready for shipment tomorrow at noon. The cruise was greatly successful; everyone will go home with really cool data, hot mud, frozen sediments, preserved bacteria mats and animals, gently simmering – nonradioactive – incubations, and mostly good memories (the bad ones fade away, Mother Nature has taken care of that). Even better, the End-of-cruise party is on the horizon, tomorrow evening at the Club Nautico in Guaymas, but of course we will NEVER post pictures from that event.
OK – we conclude instead with the obligatory group photo! Everyone finds space in front of Alvin, and we look our sunday best and smile, a bit incredulous that our cruise is soon over and that daily life waits just a few airports away. Could now somebody play David Bowie in portuguese, just for the mood?
Atlantis and Alvin will chase another adventure soon, and hunt Yeti crabs on the Costa Rica Margin (no joke, they exist). Of course, we think that the next cruise will be just like this… diving for the pot of gold at the end of the rainbow, even if we have not found it quite yet. That requires another NSF proposal, and the “pot of gold” quest has to be framed with nice null and zero hypotheses. Whatever it takes!
Today, Dec. 5, we have the long-awaited special-edition dive, the very last in this unbroken succession of eventful and/or spectacular dives. There is no sediment coring or other forms of benthic slave labor. Instead, pilot du jour Bruce Strickrott and observers Mark Lever (Aarhus University) and Nancy Cabanillas (CIBNOR) set off for an underwater scenic drive to some of the most dramatic scenery of Guaymas Basin: Big Pagoda, Robin’s and Rebecca’s Roost, the flamingo (?), and Toadstool. They are explicitly forbidden to core any more sediments, and have no push cores to do so, but they have to hunt animals with every conceivable device, including Javier’s fish catcher. Suggestion for the next Alvin overhaul and redesign: we could use add-on harpoons for the science observers. Some exciting hunting scenes would go well with the spirit of Team Zizzou.
Update 4 pm in the afternoon. The dive was a great success; Scenery, animals, even two fish (caught with fishcatcher and slurpgun) and some spectacular chimney samples for Meg. We will post some shots of the underwater scenery soon. In the meantime, here are our divers after their return, and a picture of some of their strange and wonderful catch, a most delicate deep-sea holothurian.
After this dive, it will be a while before we or RV Atlantis returns to Guaymas. The ship will have more adventures in the Pacific, then make its way to the Gulf of Mexico and the Atlantic, before returning to home port Woods Hole in 2011 for the big Alvin overhaul. In the meantime, the Guaymas aficionados will certainly work on good proposals to get another shipload of scientists back out here.
At last, here are some good pictures of the big pagoda and other must-sees in Guaymas Basin.
Today is the long-expected stormy Friday (Dec. 5), but the weather is better than expected and the dive goes forward, to the great relief of all (especially the ultra-relaxed chief scientist was wound up in pretzels). Today we feature a double newbie team: Pilot Sean Kelly takes Thomas Holler (MPI) and Yushih Lin (MARUM) for the ride. The program is pretty well mapped out: recover heat profiles, the T-loggers and three long cores each at Cathedral Hill; get various other cores at the same spot; travel over to the M14 site and yellow mat and get some more long cores there. Easy! There should be lots of time for animal hunting too. Thomas and Yushih can sit back and enjoy the ride.
The yellow mat at M14 turned out to be very bizarre when Dan Albert sprang his fatty acid analyses on us last evening: the porewater contains up to 1 millimolar acetate, that means the sediment is completely pickled with aceto balsamico de Guaymas. Where does it come from, and who eats it? We have to go back and get some aceto balsamico cores from that spot as well. Here you see the standard curve samples for the purple-blue chemical derivatives of the volatile fatty acids; Dan had to include a 1 millimolar standard, dark as octopus ink.
There is drama in chemical quantifications for those with eyes to see it!
Meanwhile, the dive team finds the Cathedral Hill mat of Dive 4565, still instrumented with the three T-loggers as left after the fourth dive. Check out the orange Beggiatoa mat in the upper left corner – this mat has almost overgrown the sampling scar from Dive 4565, of ca. 20 cm diamater. These Beggis can crawl fast, as Hans Røy knows very well by this time. Also, look at the middle T-logger. There is nothing special to the eye here; it sits embedded in a grey, powdery sediment surface. Yet, this is the hottest sediment spot on this entire cruise, 160C at 20 cm and 180C at 40 cm depth. The long cores sampled around this and the two other T-loggers were sampled VERY quickly before the plastic could melt, and they will be very interesting indeed.
There is drama for the eye down there in Guaymas Basin. The dive team stumbles onto a spectacular group of mat-covered spires. Thomas compares this one to Notre Dame and demotes Cathedral Hill to a small village church. It is a sight to behold. Bits of mats are slurped carefully and with appropriate reverance, but no coring mars the beauty of this spot. Besides, there are no mat-covered sediments.
Last but not least, Team HOT concludes their dive with good long and short cores from the Yellow vinegar mat. They return with a full sampling basket – and learn that one of the shipboard technicians, Catie Graver, broke her ankle while going out in the zodiac to recover Alvin. Catie was quickly evacuated to Guaymas that very night, diagnosed, stabilized, and is now on her way back to California for surgery. We all wish her a speedy recovery! After the elevator implosion, this accident serves as another reminder that work out here is inherently dangerous, even in the best of times.
Today (Dec. 3) we have again a calm morning with quiet seas. Perfect for a driving lesson and a newbie inauguration! The pilot-in-training is Jeff McDonald, the trainer is David Walter, and they take newbie Kai Ziervogel along for the ride. Kai is as calm and composed as possible under the circumstances, and poses here with Bruce for additional coolness.
They have a big program: Recover three T-loggers plus cores around them for UNC and MARUM; get the INSINC up (remember, the radioactive crockpot at the bottom); hunt for three hot and oily long cores, a number of Beggiatoa pushcores for shorebased collaborators, and a big slurpgunned fish for Javier (Comment: still missing Friday morning! We need that fish.). On the way up, they will collect a series of Niskin bottle water samples for chemical profiling of the water column, especially (you guessed it) oxygen.
Here you see the T-logger arrangement at the M27 mat, quite a beauty with well-demarcated orange and white Beggiatoa and brown sediments. By now we know that the T-loggers actually work; Howard has extracted the continuous temperature record of two weeks from the T-loggers at M14, and they look great. This makes the combined T-logger data and core sample sets something quite special. Note for the next time around: The T-logger handles poke out of the sediment a little, but it is obvious that this spot is not so easy to find. Next time we will need screaming, big markers attached to the T-loggers.
There is also the matter of the INSINC recovery. The radioactive tracer incubation has been sitting embedded in a nice white Beggiatoa mat on the seafloor for two days, Tuesday to Thursday (today), and has integrated over time the amount of seawater sulfate respired to sulfide, by sulfate-reducing bacteria. Now it is time to pick it up. We hope that sulfate has not run out! This will be an interesting comparison to the first in-situ incubation nearby.
Oxygen, T-logger cores and INSINC aside, the most urgent question on everyone’s mind is: Will they return safely? We assuage these fears by posting an official return picture. Yes, Kai is back in one piece, with the traditional post-dive expression on his face – the flush of scientific excitement mixed with the sheer joy of seeing the sun again.
Since this dive team is also returning the second set of radiotracer-injected INSINC cores, the swipe testing, core washing, and Alvin rinsing & hosing protocol is applied again. The radiotracer contamination swat team, Gunter and Hans, pose in the glowing sunset and make it plain that not a single cpm will make it beyond those guys undetected.
Today (Dec. 2) is a calm day with flat seas. Meg Tivey (WHOI) and Kristen Myers (Portland State University) go diving with pilot Mark Spear. They will recover the Thermocouple arrays from rocky terrain, a kind of geophysical/chemical/microbiological recording device (as fas as I see it, and Meg is not here to correct me) borrowed from the Star Trek fleet. They will also find and recover the current meter that is recording the fairly strong tidal currents at the bottom of Guaymas Basin, and on top of all that take out one of the UNC T-loggers (No. 5) with lots of long cores around it.
Alvin is launched with barely a ripple on the ocean; hard to believe that the Friday forecast calls for rough seas.
With a day delay, we post some dive pictures, but probably without really adequate scientific explanation of the devices. Meg is interested in the chemistry and mineralogy of rocks and sulfide chimneys of Guaymas Basin, and these interests take her to really nice views in Guaymas Basin. Not just mud, mud, mud and stupid anaerobic bacteria without brains. No, rocky crags and volcanic scenery! Here we go.
Original explanation from Meg: The photos show the array at Busted Mushroom and the array in the southern area, with material that has grown over the past 15 days. Data recorded at the thermocouples was
successfully downloaded, and the arrays, chimneys and loggers recovered. Back in the lab, Kristen and I sub-sampled the material. The thermocouple data are being used to provide information about how the chimneys grew, and what the temperatures were at the different places we sampled. Data from these 15-day old samples will be compared to data from 2 through 6 day old samples recovered on the last cruise to investigate microbial colonization.
Bloggers comment. A thermocouple array dangling on a rope? The rope being in fact an electric high-voltage cable in the deep sea, which in fact is salty and conducts electricity pretty well? The engineering probably is in fact quite dangerous or at least interesting. NASA has it so much easier; those guys work in a vacuum… Anyway, I am sure it is a well-considered device or NSF would not bother … By the way, by pronouncing and writing down the word “thermocouple array” I somehow insinuate to know what that is, but in fact I don’t. The way how Meg describes it, it sounds like a universal hydrothermal data transponder and mineral beaming device. But it seems to be exposed to hot vent fluid or hot rock, and dissolved ions precipitate on and around it and cover it with interesting hydrothermal minerals.
We have more remarkable pictures from the return: Meg was the only person EVER to fill out sampling forms in the sub, and to hand them over to Barbara right after her return. Here Barbara is proposing to raise Meg to the honor of the altars (catholic sainthood). The required evidence for an officially attested miracle is right there, the sampling sheet and notes.
Apocryphical postings from this blog (*censored in the early 16th century, therefore only surviving in a single late-byzantine printout from the reign of Konstantine Paleologos VIII) claim that Jennifer Biddle has performed the same miracle on her first dive, regardless of seasickness. Is this the greater miracle? Holy Rock Advocates will investigate these claims of the Sacred Mud Office.
We have a very nice morning and Alvin launch, but most people sleep in after an exhausting mud battle that went on until 4,5 or 6 am. Today we are in a more sober mood, and begin to think about what to do with all this mud – how in all the world can we ship it home? The dive program shows that we need a break. David Walter is the pilot du jour; Dirk de Beer (MPI) and Kasper Kjeldsen (Aarhus) get ready for a dive of (mostly) water column and bottom water profiling. Here they look sort of cool and restrained, but they are secretly burning with scientific excitement, and it is not about mud.
Dirk has preliminary evidence that the bottom water (a few cms above the sediment/water interface) is nearly anoxic. This has to be checked by turning the Alvin into the microprofiler motor that carries the profiler up and down in a pre-choreographed sequence, in high resolution close to the bottom. The CTD has to stay off the bottom and cannot get these data. Severe oxygen depletion at the bottom would have far-ranging implications for micro- and macrofauna alike.
The coring portion is modest; the MPI microbiologists need more hot sediments for rate experiments of sulfate reduction and anaerobic methane oxidation, to be done in the home lab. There is also a second INSINC experiment on the same spot as Monday (for consistency reasons), but this one will be incubated in-situ until Thursday. So, we can relax a little for now. Here you see (from left) Gunter Wegener, Thomas Holler (MPI), Meg Tivey (WHOI) and Alvin pilot Mark Spear having a morning chat at the launch. An important social and mercantile occasion needs to be scheduled, the Alvin Group sale. More on that later.
At the bottom, Dirk gets his Guaymas Deep water oxygen profile (about which nothing should be revealed here; wait for the report in Science) and the profiler is at last positioned on a white/greyish mat and goes through its cycle.
The INSINC is placed on a nice, hot, white mat and we try again. The radiotracer sulfate is injected into the sediment underneath, and reduced to sulfide. Since the Guaymas sediments are quite rich in sulfate, we don’t hesitate to let the in-situ incubation experiment run over Wednesday and recover it on Thursday. Next time the INSINC cores should be a little longer, to catch really hot sediment. 15 cm effective core length is perhaps a little short; WHOI and MPI cores cover max. 30 cm, and the new long cores easily up to 50 cm.
The 4 pm afternoon report from the sub is good; they got most of their program done. We hope that this evening will be as peaceful as this sunset (which is actually from Hans’ Dive 4566). But we still have a lot of core processing and dataplotting to do, just to catch up with everything.
The weather this morning, Nov 30, Monday, is much calmer than expected last week – the predicted storm has not arrived yet. We are clear for the Rockettes Dive. From left: Howard Mendlowitz in his good-luck red NC State sweater, Pilot Bruce Spring… ahh, Strickrott, and Newbie UNC undergraduate Dan Hoer in a totally spectacular pink and pale-blue whale/dolphin/seaspray T shirt. We have rarely seen such a breathtaking combination.
But they have a lot of science to do: Recover the T-loggers and in-situ incubators at our instrumented mat M14, recover long cores around the T-loggers (with unmatched long-term temperature records thanks to the T-loggers), then recover the INSINC (quietly simmering radioactively at the seabottom since yesterday), trigger, cycle and recover the in-situ profiler, and recover the lost heatflow probe that went AWOL on the last dive.
Here they core around the T-loggers at the T-logger mat at Marker 14. Four cores are arranged around each T-logger; starting here with the white mat T-logger, and then continuing with the orange mat and the brown sediment T-logger. This goes FAST. These are perhaps our best samples from a classical fried egg mat!
This dive brings up the largest single haul of mud in the history of this cruise, including the complete 3×4 long core set around the T-loggers at Mat 14, triggers, cycles and returns the profiler, recovers the INSINC, finds the missing heatflow probe, and collects various Beggiatoa and sediment cores just in case.
On return, Hans Røy, Gunter Wegener, Thomas Holler and Kasper Kjeldsen go through the carefully choreographed sequence of recovering the radioactive INSINC cores, conducting swipe tests on Alvin and cores, plus multiple washing steps. The precautions work, the tests are negative, which is highly positive.
The core cataloging procedure is quite an experience this time. The abundance of riches is topped off with two six-inch cores from yellow Beggiatoa mats. These elephants of the push core world need some special handling! This is a going to be really, really long night, from dusk to dawn…
While the Alvin dives are bringing up most of our samples, we are deploying a CTD cast every other night to collect waters for Kai Z’s project (see Who’s on board Part V).
After collecting the water, we wait on board for the moment to catch the rosette and bring it on board.
Did I mention this all happens at night? But the deck lights are on for another safe recovery!
Mark Lever is a postdoc from the Center for Geomicrobiology in Aarhus, Denmark, with strong interest in anaerobic carbon cycling by microorganisms in the seafloor. His two main research goals on this cruise are to (1) link food source to identity in sulfate-reducing, methanogenic, and acetogenic microbes, and to (2) identify patterns in competitive/cooperative outcomes between sulfate-reducing, methanogenic, and acetogenic microbes in incubation experiments with one to four substrates. Through his research,
Mark hopes to create a better understanding of the importance of seafloor-inhabiting microbes in the global carbon cycle.