The Mysteries of Ontong Java

The Final Deep

Jennifer Neale
Nov. 02 2014

Last night we steamed over the Mariana Trench, registering a maximum depth of 9726 meters (over 6 miles deep), by far our deepest sounding. It was the last major seafloor feature imaged on this impressive voyage, including mapping Kroenke Canyon for the first time. On the Ontong Java Plateau, the canyon starts in water depths less than about 2,000 meters (about 1 ¼ miles). It cuts through the Plateau with hundreds of meters of steep relief to end somewhere in the Nauru Basin in water depths exceeding 4,000 meters (about 2 ½ miles). No wonder so little was known about it. To read more about this, check out the Chief Scientist’s final entry, Mapping with Mike.

Science crew Jennifer Neale prepares to launch an XBT (ependable bathythermograph).
Science crew Jennifer Neale prepares to launch an XBT (ependable bathythermograph).Tomer Ketter

Mapping 24 hours a day is hard work. Sitting in front of screens in the control room for eight hours at a stretch, cleaning data as the data slowly come in, takes a surprising amount of energy. Yet the science party never let its attention waver. The data would be logging as it should, and without warning gaps would start to appear. No alarms would sound, and nothing would have indicated that something was about to go wrong. The science party learned to work with one eye on the data acquisition screen at all times – for hours on end. Data gaps are just not acceptable.

Note the depth in meters on the control screen. We expected 9500.
Note the depth in meters on the control screen. We expected 9500.Colleen Peters

Sometimes a bit more would be required. Late at night, it might be necessary to recalibratter column velocity, so an XBT (expendable bathythermograph) would be launched, and then we would head back to the screens for the rest of the watch. There were other breaks on watch, such as the radio show All Things Marine with Carlie Wiener. Plus, we had a video chat with two classes at a high school in Honolulu. Amelia even walked them about the ship with the laptop. They will want to meet and talk about the cruise after we are ashore.

Sunrise before going on shift.
Sunrise before going on shift.Jennifer Neale

Off watch was also busy. We celebrated seven birthdays in 20 days. There was the sea shanty night, barbeques on the upper deck, Halloween, the Crossing the Line ceremony, ship tours, great meals, and wonderful sunsets or sunrises that one normally just does not bother to appreciate. Before or after a tiring watch, to open the hatch and step out on the deck to a glorious display of colors on the horizon made it all worthwhile, as did meeting such a wonderful group of people.

Chief Scientist Mike Coffin talks with 9th graders via video about ocean floor mapping.
Chief Scientist Mike Coffin talks with 9th graders via video about ocean floor mapping.Mark Heckman

We finish today in Guam, our colleague A.J. Reyes’s home. Tonight he will take us out to have dinner and listen to music. Then the science party and ship’s crew will start to depart for their home bases or other ports of call. When the next cruise comes up, it is back to stations for the ship’s crew and back to the control room for the science party, whomever they might be, perhaps some of the same crew as this cruise, to explore new undersea frontiers. A hui hou!


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