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It might have been just another late winter storm blowing in over the Antarctic. But the crew drilling for geological samples through 5 feet of ice and 500 feet of water at Cape Roberts became concerned when the gauge measuring pressure on their drill bit began to rise and fall unaccountably.
"The pressure changes were caused by sea swells rushing past under the ice, which were making the rig move up and down like a yo-yo," said LSU palynologist John Wrenn, who had gone to Antarctica as part of the Cape Roberts Project. Palynology is the study of microscopic fossils.
When the crew realized what was happening, at about 2 a.m. on the third day of the storm, they put the rig on idle and dashed for the base camp near shore, more than 18 miles away.
"The storm lasted four days," said Wrenn, who went to Antarctica in early October to help date sediments brought up by the rig from the floor of the Ross Sea. "At times you couldn't see 5 feet ahead of you."
Wrenn, who is the director of LSU's Center for Excellence in Palynology, was among approximately 70 scientists and support personnel involved in the Cape Roberts Project, one of the largest projects ever put together to study the Antarctic continent. The purpose of the project is to understand the formation of the Transantarctic Mountain Range as part of learning how this southernmost continent evolved.
He was not caught on Cape Roberts when the storm hit. Instead he was caught inside the National Science Foundation's new Crary Laboratory at McMurdo Station, 80 miles away, where he was stuck till the storm blew itself out. It was a condition-one storm.
"There are three stages of weather alert. When you're in condition one, there's a whiteout. Everything's white; you can't see and the winds are really strong. The winds reached 70 to 80 knots (more than 90 miles per hour) and some people were blown over and rolled down the street. When you're in condition one, you're restricted to whatever building you're in. Nobody leaves the building. Most of this storm was a condition-one storm."
For navigating in less serious conditions, ropes had been strung from building to building. "In condition two, you can still see, but you need these ropes to help guide you anyway, and to help you so you don't get blown over.
"One of the people who was there during the winter told me they had a real bad storm that blew over a plywood box of mattresses they were moving from one building to another. They stood there and watched from inside a building while it broke this box into little pieces by rolling it down the street, and then the mattresses took off. He said the mattresses, which were twin-bed mattresses, were flying through the air like magic carpets. They found some later that had been blown 40 or 50 kilometers (about 30 miles) across McMurdo sound and ended up against the Transantarctic Mountains.
"The weather rules everything down there," he said.
As it turned out, the storm didn't hit the Cape Roberts base as hard as it hit McMurdo. Scott Borg, director for the Antarctic Geology and Geophysics Program within the Office of Polar Programs for the National Science Foundation, who was in charge of approving and funding science proposals for the Cape Roberts Project, was at the cape when the storm hit.
"I was hoping to make an hour-long visit at the rig, and an hour-long visit at the camp," he said. But while he was at the camp, the storm closed in around McMurdo, and the helicopter pilot who had flown him out was told not to return to McMurdo. The pilot was, however, able to fly the crews from the rig to the base and back for the next day and a half.
When the drillers went back to their rig after the storm, they discovered that open water, which had been three miles away, was now little more than half a mile away. Cracks 5 feet long had opened up in the ice around the rig. Further drilling was canceled.
"The rig was in good shape, and we could have gone on drilling but the rig was on a tongue of ice that projected into the sea, and was not protected from southern storms. So we decided to cancel the drilling," Borg said.
Wrenn said, "There was a real danger that the ice would break off between the shore and the rig, sending the whole rig north to Australia. Or worse, break up and send it to the bottom of the Ross Sea."
Large bulldozers pulled all the rig components, which were on skids, back to shore within a day. The rig had been operating for less than a month and had drilled only 500 feet. Original plans called for drilling two 1,500-foot cores at different sites under the Ross Sea.
Storms of that magnitude usually come in the Antarctic winter, when warm air that has risen from the equator and drifted south is cooled over Antarctica and suddenly drops, causing strong winds to blow north. (Every direction is north from the South Pole).
The aborted drilling season was a big disappointment to scientists who had spent a year or more preparing for the trip, but most of them took it philosophically.
"That's Antarctica, after all," Borg said.
Peter Webb, a professor in the geological sciences department of Ohio State University who has made more than 18 trips to Antarctica said, "If I can get three solid weeks out of eight I feel like I've had a good time."
What was found in the abbreviated drilling period was still worthwhile. "We expected to find 25- to 30-million-year-old sediments, but we found 17- to 18-million-year-old sediments. It is a time period that is not represented anywhere else in that area of the continent," Borg said. "That's an important part of the record."
Wrenn said the rig brought up some interesting cores with some good samples. The cores were a mixture of fine marine sediments mixed with chunks of rock and boulders that had rained down onto the seabed from the bottoms of melting glaciers and floating icebergs.
Although the scientist's time was short, their days were long. Wrenn said all he did was work, sleep and eat during his six-week stay on "the ice," as old hands there call it.
"The shortest day I worked was 12 hours. Since it doesn't get dark (during the Antarctic summer), your biological clock doesn't get cued. Most of the time we worked 14 to 16 hour days."
There is also pressure to get as much done in as short a time as possible, he said. Most researchers are aware of the high costs involved in getting them and their equipment to the Antarctic and of the limited time they have on the "ice," and they want to make the most of it. Wrenn said he didn't notice the long hours because he was absorbed in what he was doing.
What he was doing was studying dinoflagellates, microorganisms that leave behind tiny "cysts" that endure for millions of years. Because new species evolve over time, specimens in a core sample give an indication of how old that sample is.
Wrenn freed the cysts from the core samples with a $13,000 microwave rock digester, paid for by the National Science Foundation. The digester, which uses hydrochloric and hydrofluoric acids in conjunction with microwaves to dissolve the rock, not only speeds up the digestion of sediments but also limits the quantity of acid vapor produced. Because of strict environmental concerns, acid vapors cannot be released into the Antarctic atmosphere; they must be neutralized.
Because they did not get as deep, therefore as far back in time, as they had hoped, Wrenn did not find very many dinoflagellates. Dinoflagellates prefer warm waters, and the waters around Antarctica used to be warmer than they are now because of a land bridge that once connected the Antarctic to South America. "During the Oligocene (about 36 million years ago) major changes in the Antarctic really began," Wrenn said.
When the land bridge disappeared, a current began to flow in a circle around the continent, isolating it from the warmer waters of the rest of the planet. "When that happened the continent just became colder and colder and colder -- it's essentially the air-conditioner for the planet now -- and any organisms that liked warm water were killed off or moved to warmer water. That's essentially what happened to the dinoflagellates."
As it turned out, the diatoms were the most valuable fossils found in the cores. Diatoms, which leave skeletons made of silica, are common in cold-water environments.
"The ages (of the samples) were all based on what the diatoms had to say. We couldn't add anything to the ages because, for one thing, dinoflagellates were pretty sparse, and for another, there were a number of new fossils, and we don't know what their ranges are."
It's a simple life at McMurdo. Other than your work, there is little to do but read and watch movies, although there are a couple of bars down there, Wrenn said. There is no real free enterprise in Antarctica, and the bars used to be run by the U.S. Navy, which was in charge of all Antarctic support, but the Navy is being phased out. Now a private contractor out of Denver, Antarctic Support Associates, is doing most of the work.
"Antarctic Support Associates is in charge of the Crary Laboratory, maintenance on the base, cooking, supplying people like plumbers, electricians, carpenters, computer people, truck drivers -- just about everything down there. They were also in charge of getting the supplies we needed to do our palynology. There were a number of rounds of going through catalogues and filling out supply forms, checking with them about what they'd ordered and what they were going to substitute. There's a lot of up-front planning to be sure that we had everything we needed. You can't run to the supply store for a beaker.
"McMurdo is unique. The whole reason for this village to exist is science. I don't know if there's any other village on earth dedicated just to science."
The Cape Roberts Project will continue next year.
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Pictures can be found at http://appl003.lsu.edu/UNV002.NSF/d8b9f5fe9b94e684862564920056dd4e/c1bf9dd80ece72398625658e00756e2f?OpenDocument
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