Easter Microplate Expedition
March 21, 2005 Day 10
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Alvin dive# 4087,
Finally the first dive! Neptune was kind today and even though the weather was gray and spitting drizzle, there was little wind and the seas were calmer than expected. The Alvin was launched promptly at 8:00 AM, and they found a black smoker by noon! Nicole was wearing her lucky necklace, and at launch we saw a bird (guessing a shearwater; this was our first bird sighting this trip, though they saw five yesterday from the bridge) and a rainbow, which we took to be good signs (and we're not particularly superstitious).
The Alvin during launch, suspended from the A-frame with the swimmers giving their sign for good fortune. Mark, on the left, later took several of the photos below from the zodiac. Photo by Dan Layton-Matthews, Univ. of Toronto
Bob and Nicole were the observers, and Gavin was the pilot. The descent to 2200m took about 2 hours. There was not much bioluminescence, which is consistent with the general lack of birds and fish suggesting that there is little biological activity in the surface waters here. But the deep blue of the Pacific was impressive. (Photo on right: The Alvin as it descends. Photo by Mark Spear.)
When they landed on the bottom they started looking for hydrothermal activity. They found young, shiny, glassy, iridescent lobate lava flows and sheet flows, with older, beaten up lava pillows sticking up through the younger flows. No fissures were seen. They drove across-axis then came back because the flows began to look older.
The rest of us on the surface ship did what we could to look relaxed, as if it was just another day, but we couldn’t keep our eyes off the electronic board showing some information about the progress of the dive, or running up to the "top lab" where the underwater phone calls from the sub are received. At lunch time came the news—they had found a chimney!
Most of the rest of the dive was spent sampling around the new chimney, named “Sebastian’s Steamer” (after little Sebastian, Nicole’s son). A central, 3m tall, narrow spire venting black, particle rich fluid, surrounded by smaller beehive structures venting clear shimmering water with temperatures up to 187ºC make up the site. It appeared to be a relatively young vent: it was sitting directly on pillow lavas and there was no collapsed sulfide rubble. Bacterial mat from base to top, alvinellid worms and an extraordinary number of crabs are, at first sight, the dominant inhabitants of this new dot on the map. A strong current from the north carried water that was quite turbid, so there may be other vent sites in that direction.
The smaller mound nearby is venting very hot, clear, shimmering water. Alvinellid worms and bacterial mats are on the surface.
The whole dive was 9 hours. They brought samples of glassy, black lava "pillow buds", bacterial mats and alvinellid worms including Alvinella pompejana, the “hottest” animal on earth. Pompeii worms get their name after the Roman city of Pompeii that was destroyed during an eruption of Mount Vesuvius in AD79. The worms, found in large aggregate colonies enclosed in delicate, paper-thin tubes, have been found to thrive at temperatures of up to 80ºC.
This was Nicole's first dive, and Bob can't recall how many he's had (he's old!), and they were the first to see this spot in the ocean. It was Gavin's first solo dive; he had been a pilot in training and always driven under the supervision of a pilot in the sphere with him. To commemorate the event the Alvin group had prepared a small surprise for him: a few buckets of ice water followed by flour, eggs and maple syrup! What a baptism! Since it was the first dive for Nicole, she couldn’t escape a couple of buckets of water herself. This is the farthest south the Alvin has ever dived and that the ship has ever been, and it is the farthest south that hydrothermal vents have (so far) been found. There were many milestones today!
Gavin receiving the honors bestowed on a newly certified Alvin pilot
Tonight we dredged over the Foundation Seamount to the west of the dive site, and got back red and yellow oxidized chimney material and no obvious signs of active hydrothermal venting. While some of us are sorting the samples in the different labs of the ship, the rest are looking at pictures and videos captured during the dive in order to prepare future dives in this same site. Tomorrow morning we will be back at 38ºS and, if everything goes well, Alvin will be in the water at 8am.
–Jenny Paduan and Ana Hilario, with Nicole's help
Today was Alvin's first dive this expedition—the moment we had been waiting for throughout the entire transit. Most of us woke up early to get our first glimpse of
Alvin in action. Getting her in the water is a complicated procedure involving many people. My contribution was standing back and taking a bunch of pictures.
We spent the day waiting for reports of what the people in the submarine were seeing. Around 12:00 there was an announcement: a black smoker had been found!! This was a very exciting discovery; smokers have not been found this far south before. Another report from the top lab—the black smoker is in communication with sea monkeys! I don't know about that one, but even if it isn't true it was exciting hearing what was happening on the ocean floor. We didn't find any mussels today and the mussel pots came up empty, but it was still a successful dive and we were able to survey some of the surrounding area.
Tonight we are preparing for tomorrow's dive. Cindy and Michele are going, so they are rounding up warm clothes and clipboards. The mussel pots have been tucked in the science basket again, ready for another trip under the sea. Hopefully tomorrow we will find mussel beds, the primary target of our lab's research.
The R/V Atlantis and rainbow from the zodiac during launch. Photo by Mark Spear.
All underwater photos were taken with the submersible Alvin, and are courtesy of Woods Hole Oceanographic Institution.