Dive and Discover : Expedition 1 : Daily Updates

Daily Update: Dive 3517
January 14, 2000
By Dr. Dan Fornari and Dr. Susan Humphris

There is great excitement on board tonight! Everyone is zooming around, processing samples. The scientists are now attempting to culture (grow) the microbes that they brought up from the hydrothermal vents!

The seas calmed down quite a bit overnight. The partially cloudy sky resulted in a spectacular sunrise. Anna-Louise Reysenbach and Don Nuzzio boarded Alvin at 0800 hrs this morning for Dive 3517. Their goal was to visit several vents and collect samples for the biologists and chemists.

With Expedition Leader Pat Hickey as pilot, they visited five vent areas and collected eight “Sipper” water samples, four sulfide samples (two for molecular work on the microbes, and two for culturing), three cores of sulfide-rich mud, and many vent animals.

During the day, everyone was busy with some activity. George Luther prepared the chemical sensors for the next few dives. The tips of the sensors have to be polished until they are smooth. George then adds a drop of mercury to the end. This is a difficult job on a rolling and vibrating ship! Alice Ortman and Melissa Kendall reviewed and analyzed the videotapes from yesterday's dive. On deck, Jeff Benitz and Jerry Graham of the Deck Department got a little painting done so the ship stays in good shape.

The weather got better as the day progressed. A pod of pilot whales visited us in the afternoon. As usual, the crew recovered Alvin efficiently. Anna-Louise and Don excitedly told the gathering scientists all about the bacterial mats and hydrothermal vents they had seen. Pat was the first to notice burn marks on the equipment at the front of the basket. Alvin had gotten too close to a hot vent!

The excited scientists removed the samples from the basket and brought them into the lab as quickly as possible. Once in the lab, Tim Shank pulled long tubeworms from a bucket. Luis Hurtado put small segmented worms in tubes. Other scientists collected material from the rocks so they could start culturing the microbes. Some of the scientists will continue to work well into the night. Others will get some sleep to prepare for the dive tomorrow.

Today was also the start of the cruise Ping-Pong tournament. There were several matches today. The Ping-Pong table is in the main lab, so people who are not working can enjoy a game and relax a bit. The competition is fierce. The ship’s crew and the Alvin team have practiced hard! Check back to see who wins!

Dive Summary
On Bottom: 0919 hrs.
Off Bottom: 1505 hrs.
Maximum Depth: 2019 meters

Dive 3517 was very productive. Pilot Pat Hickey, Anna-Louise, and Don found and sampled several hydrothermal sulfide structures. Pat said that he was impressed by how many vent structures there were in the area. "Every time we turned on the scanning CTFM sonar, we saw targets, so it was easy to drive around and find them." They were interested in sampling the ledges that protrude from the sides of the sulfide structures. These ledges, composed of iron sulfide minerals and barium sulfate (barite), trap pools of hot (300°C, 572°F) hydrothermal fluid beneath them. Paralvinellid worms live on the surface of the ledges where the temperatures are only 30-50°C (86-122°F). Microbes like living in these cooler places on the ledges.

In addition to sampling these ledges, they took Sipper samples, made temperature measurements, and used the chemical sensors to learn about the environment where the microbes are living. They also collected several different types of worms (including tubeworms and segmented worms) from some of the lower-temperature vent sites.