The Day That Lasted Two Days

Today’s story starts yesterday evening, and it features valuable items lost at the bottom of the sea, a midnight rescue plan sketched out on a napkin, a grappling hook as tall as a person, and a creature that looks like a space flower.

We had come to Cape Adare to help Bruce Huber of Lamont-Doherty Earth Observatory retrieve some data. Bruce is interested in the way very deep, salty water leaves the Ross Sea and joins the world’s ocean circulation.

Since you can’t station a ship year-round in the Ross Sea to measure deep currents, oceanographers have designed tools called moorings that they can leave in the water to do the work for them. They consist of an anchor and a length of cable to which sensors such as current meters and temperature sensors are firmly clamped. A buoyant sphere at the top of the cable keeps the whole mooring standing straight up off the seafloor (see this diagram)

Three years ago, Bruce had ridden on the Palmer to this very spot off Cape Adare. The Palmer had to break through several miles of ice to get here that year. He had dropped two moorings into water about a mile deep. The instruments had memory cards and enough batteries to last for the three years they would spend in the cold bottom water. Now, he had come to get them back. Read on through the slideshow to see what happened:

Getting the first mooring back was a huge victory for the Palmer’s scientists and crew. Last month, another expedition had tried the same kind of grappling rescue on three faulty moorings—without getting a single one back.

So at 11 a.m., while the first mooring’s instruments were still wet, we started on the second mooring. By 4 p.m. it was clear the effort had failed, but Dr. Kohut thought the data were valuable enough to give one more try. The marine technicians rewound the winch cable, reattached the grappling hooks, and started over. At 9 p.m. Dan Ohnemus, a graduate student at Woods Hole Oceanographic Institution, let out a whoop as a yellow float broke the surface. By midnight, 24 hours after the rescue had begun, the marine technicians were bringing the mooring’s instruments on board.

We found the last sensor hanging at the end of the mooring cable. The grappling hook had caught it, ripped loose the clamps fastening it to the cable, and snapped the mooring cable itself. The only thing holding the instrument to the cable at all was a plastic zip-tie—the kind you buy in bags of a hundred at a hardware store—which had been put on as a final safety measure.

I was amazed at the ingenuity of the scientists and marine technicians in planning and attempting this rescue. I was also impressed by the tenacity and faith in their projects that oceanographers must have. Over his career, Bruce has successfully retrieved 14 out of his 16 moorings.

Still, three years of his work hung on the correct operation of an acoustic pinger and a heavy metal hook at the bottom of the sea. I tried to imagine what it would be like to have planned something three years ago whose outcome I wouldn’t know until today.

Bruce just pressed on: he asked for a final CTD cast to gather data about the water before the Palmer left. Then, for the first time in 37 hours, he went to bed.

Bruce Huber’s work in the Ross Sea is part of a collaboration with Dr. Arnold Gordon, also of Lamont-Doherty Earth Observatory.

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About Hugh Powell

Hugh is a staff writer at the Cornell Lab of Ornithology and is on special assignment with the Rutgers University Institute of Marine and Coastal Sciences. He has previously written for the Woods Hole Oceanographic Institution.

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