Hess Deep Home














Expedition Dispatches


Dispatch No. 6


Thursday, March 25, 1999 23:16:00 GMT
From Monte Basgall, Duke University Senior Science Writer
Location: 2 degrees, 22' N; 101 degrees, 12' W
Weather:

  • Wind: 9 knots
  • Seas: 3-5 feet
  • Skies: partly cloudy
  • Air temperature: 81 degrees Fahrenheit
  • Seawater temperature: 86 degrees Fahrenheit

  • There was a pause in most Hess Deep operations Wednesday, March 24, so watch schedules could be readjusted for today's start of daily dives by the manned research submarine Alvin. It was a good time for scientists and a supporting staff of Woods Hole Oceanographic Institution technicians and engineers to catch up on sleep.

    Seizing the opportunity, though, Hess Deep co-principal investigator Emily Klein and doctoral student Michael Stewart, both of Duke University, used the off time for an extra sampling project that took the R/V Atlantis 30 miles north of Hess Deep. Together with James Brophy of Indiana University, Stewart's former advisor, the Duke geochemists spent the afternoon and evening there dropping five 100-pound "wax corers" about 11,500 feet into the water to smash and pull up special glassy lava fragments from a place where another mid-ocean ridge is just beginning to open (wait for next dispatch).

    At about 5 p.m., amidst that coring project, scientists, the Woods Hole support group, and the ship's crew began gathering on the aft main deck for an Atlantis-hosted cookout and party in the very shadow of the open fronted hangar where Alvin waited to begin its work, its folded manipulator arms making it appear crustacian-like.

    Altantis steward Carl Wood, whose menus are constantly varied and innovative, stood behind a grill serving up steak and chicken, while the spread on a nearby table included shrimp and tuna. For some who had spent most of their recent time in the darkened interior of the DSL 120 and Argo II control van, it was an opportunity to see people in the daylight and talk about other things besides dike fields and gabbro. As the equatorial sun descended, the food was followed by dancing that lasted until well past dark - the spirit hardly dampened by a sudden rain squall.

    Today began early for Stewart and for Hess Deep chief scientist Jeff Karson, both of whom were about to descend on the first of 15 planned Alvin dives. When they showed up at 7 a.m. for breakfast, the mood had overtones of those ritualistic astronaut pre-launch meals where the media listed the menu. Stewart had a few slices of French toast while Karson piled on generous helpings of oatmeal, fruit and bagels to steel himself for "a long, cold and damp day," he said.

    While both were starting the day in loose T-shirts and shorts, they had already left warmer clothes in special blue buckets for early loading on the submarine along with film, notebooks and other supplies. The trip would take more than one hour each way, at a speed of about 100 feet per minute. After Alvin began it's long descent toward the 39 degree Fahrenheit water in Hess Deep, Stewart would slip on a sweatshirt, sweatpants, wool watch cap and wool socks; Karson's diving clothes would include a wool Ecuadorian sweater.

    Karson has previously gone down in the Alvin "30 or 40 times," he estimated. Despite his veteran status, he also admitted being anxious,especially since this would be the submarine's first descent in this series.

    "I think that anxiety will disappear when we get to the bottom and see rocks," he said.

    In an earlier interview, Karson acknowledged always being mindful that there are "a couple of miles of water over you and the pressure is enormous. If you think about it too much it could definitely freak you out," he added.

    Today he compared Alvin dives to "going to another planet. There's no weather, no erosion, no rain, no wind, no sunlight," he said. "The rocks are somewhat different from rocks up on the continents. We're constrained by a watery environment, a different environment, that geologists find very frustrating because they can't reach out and grab any rock they want and look at it."

    Stewart, who would be making his first Alvin trip, said pre-dive nervousness and a pitching boat both made him sleep poorly. "It's like going to the moon," he added. "Very few people have gone down to the bottom of the ocean. You could probably count them in the hundreds now. It's the last great frontier on Earth really."

    The research submarine Alvin dates back to 1964, though it has been overhauled and updated so many times that nothing of the original craft is left. It was named both for Allyn Vine, the Woods Hole scientist who championed its construction, and for a once popular cartoon chipmunk.

    Over the years it has helped locate an H-bomb lost in the Mediterranean after two US aircraft collided, and it also photographed the famous sunken ocean liner HMS Titanic. But mostly it does research dives like this one at Hess Deep.

    Within days of boarding Atlantis, Hess deep scientists and students went through an Alvin tour that began with the question "Have you ever dived before?" The orientation also included a long list of "Do Nots."

    No one should step on a hatch seal, or wear synthetic attire (lint) nail polish (flammable material) or makeup, lip balm and lipstick (too greasy). Aromatic cologne is out too because of the close confines of the closet sized cockpit. Touching the acrylic plastic portholes is a special concern (the slightest abrasion could prove disastrous at deep ocean pressures). A safety briefing was also lengthy. There are contingency plans to deal with power loss or disruptions to the breathable air supply.

    There are multiple ways to return to the surface if the usual system fails or if the pilot became disabled. There are stores of emergency food rations, fire extinguishing equipment and vacuum-packed down sleeping bags. There is aspirin to relieve headaches brought on by higher than normal carbon dioxide concentrations.

    There was a walk thorough Alvin's equipment too. It is able to move at speeds of up to two knots, and can rise, hover, drop or settle on the bottom. It has six external cameras (four video and two still), 10 lights to illuminate the pitch darkness, two robot manipulator arms to grab and remove rock samples, and sample baskets to bring specimens to the surface.

    Climbing through the 20 inch diameter hatch requires reasonable fitness, and spending a day folded into the two seatless observer positions (the pilot shoehorned in between) tests for both claustrophobia and endurance. To ease the burden, there are supplies of coffee and water on board, as well as a rudimentary lunch (including peanut butter and jelly sandwiches). And, while there is no restroom, there are official HERE ("Human Element Range Extender") bottles.

    To make the most of such exceedingly rare opportunities, scientists diving in the Alvin must stay on their toes as they sit in the dim cockpit surrounded by soft glowing instrument lights. There are hand held cameras to aim through the 3.5-inch thick optically distorted windows. There are paper maps and record logs to fill out and coordinate with navigation readings and the time of observation. There are outside cameras to check, video recorder tapes to monitor, and tape recorders to talk into constantly.

    "No amount of description is too much, so keep talking all the time - tape is cheap," said a diving information form Karson distributed to the Hess Deep research team. Likewise, "do not hesitate to take lots of pictures," it added. "Film and disk space are very cheap." The form also reminded scientists to collect samples "systematically" with Alvin's manipulator arms and record all information possible about the specimen, including where it is located in the collection basket.

    Primed and keyed up, Stewart and Karson stepped into the bright sunlight near Atlantis's rear fantail, where the grey-white, titanium hulled Alvin had been rolled out along a curved track earlier in the morning. It was now attached to an A-frame crane, with a stair ladder leading up to its snub orange conning tower.

    About 7:50 a.m., the pair got the word to climb that stairs, one after another, and wriggle into the open hatch. Hanging by a $10,000 five-inch-thick, beautifully braided rope that can support an 86,000-pound load, the 38,000-pound Alvin was soon lifted off its wheeled carriage and lowered into the tossing blue Pacific.

    Then a black-pontooned Avon motorized raft carrying two flipper clad "swimmers" zipped through the water to meet it. As Atlantis moved forward and away from pitching sub and raft, the swimmers jumped into the water to begin last minute preparations.

    Back on Atlantis, other members of the science crew climbed to an upper deck to make photographs of the descent, which would begin after one swimmer opened a valve that lets seawater rush into a ballast tank. Standing in the hot sun with cameras poised, the watchers waited, checked their watches, and begun wondering why it took so long.

    The "top lab" Alvin communications center, located on Atlantis's bridge, had the answer. As soon as the submarine hit the water, a vital computer link called the "data logger" had stopped working, leaving Alvin's overseers debating whether to cancel the dive. The data logger channels data from on board clocks, video recorders and navigation sensors to the on-board master computer that serves as an information coordinator. While clocks, recorders and navigation may be working just fine, researchers will still lose the ability to get proper time and navigation fixes on video and other observational data if the data logger can't send the master computer that information.

    Proper navigational coordination is also crucial to calibrate a special Duke-designed geocompass that rides outside Alvin. A cylinder mounted inside a boxy frame, the geocompass contains tilt meters and a magnetic compass to establish the alignments of interesting geological features once Alvin's manipulator arms place the device next to those structures.

    Alignment is hard to impossible to judge without the geocompass, because researchers' sense of perspective is skewed by optically-distorted windows that point slightly down rather than horizontally. What is horizontal isn't clear either in the small cocoon of light Alvin operates in.

    Without information from the geocompass, Karson and Stewart could not "orient" some of the rock samples as they collect them, one big goal of the Hess Deep project. But, despite this and the other handicaps, they decided to go down anyway, since the alternative was one-less dive.

    Alvin finally disappeared beneath the waves at 8:25 a.m., arriving at the Hess Deep working depth at about 10. Between then and 2:15 p.m., the two collected about 200 pounds of rock along a 2,100-foot course that took them along a field of dikes, then up into a volcanic area. With their power beginning to ebb (it takes several dives to completely charge the batteries), they elected to began their ascent at 2:16 p.m., a process that involves dropping weights to increase Alvin's buoyancy. At the expected arrival time, other scientists congregated with their cameras as the Avon drew a big circle around the water in front of Atlantis's bow. The first sign of the submarine was a seeming blue flash -- an illusion produced by the combination of dark blue water, grey-white hull and bright afternoon sun.

    After Atlantis swung around, and the Avon connected a tow line, Alvin was hauled back on board and the stairs returned to the conning tower. Karson and Stewart emerged, clasped hands in a victory salute, then walked down the ladder while other scientists applauded. Then Stewart, the first-dive novice, got thoroughly doused by two buckets of cold seawater. "It was so cool," he recalled the cockpit ambiance aboard Alvin. "Lots of beeping and lights flashing."

    After the still-dripping Alvin was rolled back to its tall deck shelter, Karson and Stewart began carefully placing their collection of black-tinted rocks into plastic bags, one by one, after first writing down their numbers and their positions in the sample boxes. As soon as the bags were loaded, fellow researchers put them in large white plastic buckets, then carried the buckets to a nearby "wet lab," where they will be catalogued and cut into samples under Klein's supervision.

    Karson then called for a short science meeting in the main laboratory, where both he and Stewart reported great success and interesting observations.

    "The bottom line is that the exposures were unbelievable basically all the way up," Karson said. With the Hess Deep rock so clearly exposed, they were able to see and sample a "fantastic" complex of sheeted dikes. Up in the volcanics area, he also found that dikes had intruded into pillow lavas, and that both lavas and dikes had been shattered by unknown geological forces.

    By the evening, an excited Karson was back in the computer laboratory watching as the videotape record of the first dive played back on a TV monitor. There were enough sharp images of dike complexes and other features - taken with a "three chip" digital camera - to keep the researchers glued to the screen.

    By about 9:30 p.m., Woods Hole computer specialists had identified the source of the data logger problem, a failed sensor that caused the logger's software to crash. It was promptly replaced.



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