On To Day 4Back To Day 2Day 3. Data Collection Begins

September 28, 1998. Today the data-collection began. Everybody gathered on the deck to snap pictures of the first core sample, then of the crane lowering the DSL 120 into the water.

During the previous 12 hours, the engineers and officers had performed the tedious task of locating where each transponder had landed. They did so by signaling each transponder and calculating its distance from the ship based on how long it takes for the transponder to respond. The engineers then zero in on the transponder by guiding the ship in a half-circle around it. Fortunately, the transponders landed close to their targets. There was some concern that the current could have pushed some of the transponders down the steep slope of the ridge.

Wax CorerDropping The Wax CorerBy mid-afternoon, the location of the last transponder was plotted. It was time to take the first of many samples from the ridge. The first site was just off shore at a depth of 456 meters. The device we are using to take these samples is called a wax corer. It is decidedly low-tech and quick and easy to use, enabling us to take many samples. It is really nothing more than a heavy cylinder. At the foot of the cylinder, there is a disk with six cups facing downwards. The head also has a disk with seven cups that face out perpendicular to the cylinder. Each of these cups is filled with a soft, sticky wax. To collect samples from the ocean floor, we attach a cable and drop it over the side of the boat. The cylinder sinks to the bottom foot first. When it hits the bottom, pieces of the ocean floor stick to the wax in the cups. We then reel the cylinder back up and pick the material from the wax.

Sand from Puna Ridge embedded in the wax.These small samples can tell us a lot about the history of the area. For example, a lot of fresh glass indicates a relatively young lava flow. A lot of sediment indicates a much older flow. We will be taking numerous samples like this all along the ridge.

The crane lowers the DSL-120 into the waterRight after the samples were collected, the engineers lowered the DSL 120 into the water. The DSL 120 contains a side scan sonar system that will create a detailed map of the ridge and give us information on the composition of the ridge. For the next 35 hours, the ship will pull the DSL 120 the full length of the ridge at a speed of one knot. We are hoping to map eight swaths over the next couple of weeks.

Go back to day 2. Go to day 4.