Florida State University : Research in Review

Day 6 - Thursday, 09/18/08

Position: N42 33.872 W32 00.190

Arising at 6:30, I soon learned that over the evening two successive casts had come up empty, their cocking mechanisms apparently having been inadvertently triggered on the descent. Theory was that the pitching boat was the culprit, putting just enough slack in the cable to trigger the devices. Around 3 this morning, with winds gusting to 35 knots, Capt. Jeff finally called a halt to operations, and a tired, wet night crew headed for bunks.

By 8 a.m. we were optimistic that a near-calm wind, albeit a confused sea—we witnessed 4-5’ swells coming from not one but three directions at the same time—would make our next cast a winner. This time, I watched the instruments in the wheelhouse, over the right shoulder of Jack, who sat at the controls of the massive winch just below him. His perch gave him a perfect view of all operations astern. Capt. Jeff stood nearby, hands on the Sur’s controls.

Buz had replaced Andrew at the sonar controls on main deck. A marine technician himself in a past life until, in his own words, he “screwed up and got a Ph.D.,” Buz was in his element. Despite the recent setbacks, his optimism was palpable. Buz was clearly enjoying this cruise, his first extended one in 15 years.

As Buz counted down the corer’s descent—“Bridge: Seven hundred fifty meters, seven-five, zero, over.”— through the intercom, Jack kept watch on his screen that showed the tension, measured in pounds, on the cable. As the boat pitched, the tension ranged from 1,495 pounds to 1,100. Jack said he would know when “the package,” shipboard parlance for the corer suspended two miles below, hit the bottom before Buz would, just by seeing his tension graph plummet.

“Two hundred meters, bridge—two, zero, zero.” The corer had reached the depth all agreed should be just right for the final descent.

Capt. Jeff eased back on the ship’s throttles and slipped the engines briefly into reverse. The ship’s speed-over-ground, just over a knot, ticked down to zero, and then went minus. The Sur was being dragged backward by six tons of corer and cable suspended from the crane on its fantail.

“We’ve hit bottom,” Jack said. The squiggles on his monitor showed a dramatic drop, from around 1,150 pounds to just over 800. Buz’s voice crackled over the intercom. “The package is down, bridge, the package is on bottom.” In five seconds, it’s all over, and Jack has pushed the winch throttle forward. The corer is coming up, and at its normal rate of 60 meters a minute. Jeff had ordered the descent at 40, hoping this would help matters. “Well, we’ll know in an hour what we did,” Jeff said. “I feel good about this one.”

But it wasn’t to be. This time the corer came up much as it did the first time we dropped it Tuesday morning—full of nothing but seawater. Chief Scientist Thistle and Buz huddled with Jack and Andrew to assess the problem. Three successive failures was threatening to put a kink in the mission’s work schedule—three other latitudes awaited sampling far to our south.

Collective wisdom had it that somehow, the triggering mechanisms were getting fired on the descent, shutting the coring tubes bottoms prematurely. Nothing else could explain the total lack of sediment picked up on the previous three casts. Sea conditions were probably playing a role—we were now experiencing the roughest conditions so far, although Capt. Jeff assured us that what we were seeing was nothing compared to the pounding this region normally doles out to mariners. And as preparation began for the next assault on the seafloor, the troubled waters began to lay down dramatically. The sea gods were continuing to smile on the Point Sur.

For this next cast, launched at 3:20 p.m., the crew decided to try re-installing the wood frame at the base of the multi-corer module. It was simply a matter of looking at all the variables—and since the wood had been removed last night, every cast had failed, whereas on Tuesday, all but the first went fine, albeit in a bit calmer water and roughly 3,000 feet shallower!

Being beyond reach of the Internet, I asked and received permission from Capt. Jeff this afternoon to use the Iridium sat phone in the bridge to phone home. I had no trouble getting Christine Suh, my associate editor, on the first ring at her home. It was comforting to hear her familiar voice. I assured her all was well and hoped to regain an e-mail link by Saturday. She reported that our “Research in Review Goes To Sea” blog site—created just for this cruise—was up and running. The blogosphere swells!

Our luck with the corer turned dramatically in our favor late this afternoon. Now re-fitted with its wooden base, at 6:30 the apparatus swung on deck with eight solid cores—all in excellent condition. A new record! A tired crew was elated. At 9:30, yet another cast came up, this time with six good cores albeit strangely missing yet another tube. Apparently, the corer likes its wooden shoes! We redeployed at 10:17 under a rising full Pacific moon, and the “day shift” retired for the evening. Luck continued for the night shift, which worked into the wee hours retrieving more good sets of mud.

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