Digging deep - Digging Deep Revolutionary technology takes...

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Unformatted text preview: Digging Deep Revolutionary technology takes archaeologists to new depths. MARIANNE ALFSEN tiny crawfish p0pped out of a 300-year-old ceramic jar and stared in disbelief at the creature threatening to evict him from his home. At 560 feet down on the muddy bottom of the Norwegian Sea, visitors from the surface are rare—even more so when its a hulking, brightly lighted robot reaching a hydraulic arm toward you. High above the jar, in the control room of a research ship, the technician running the remotely Operated vehicle (ROV) watched a camera screen as he steered the robot's arm around the jar, nimny avoiding the field of fragile wine bottles and Asian ceramics that lay half—buried in the mud around it. The thick tether connecting the ROV to the control room transmitted a response from the robot’s hydraulic “fingers,” essentially enabling the operator to “feel” the object as he watched himself pick it up through the “eyes” of the remote camera. As the jar was carefully deposited in a basket for delivery to the surface, the now homeless crawfish hurriedly swam away. Originally developed more than half a century ago by the U.S. Navy to locate weapons and ships lost in depths beyond the reach of scuba divers, increasingly more sophisticated ROVs are now commonly used by world navies and natural-resource industries for deep- water exploration and construction. The first glimpse of robots’ enormous potential in marine archaeology came in 1989, when a team led by Robert Ballard and Anna Marguerite McCann used an ROV to successfully investigate and sample a late Roman wreck more than 2,000 feet deep near Skerki Bank, off the coast of Sicily. Since then, engineers and archaeologists have endeav- ored to advance from mere visual survey and random removal of artifacts with ROVs, to full-blown robotic excavations. 99 There were two major problems to solve in excavating underwater sites with ROVs. First the robots, which gen- erally operate independently underwater, attached only by a tether to the command vessel, are bulky and weigh hundreds or thousands of pounds; there is a risk that they may disturb or even destroy the very sites they are sent to investigate. Second, accurate and delicate maneuver- ing of an ROV (which relies on powerful thrusters to maintain a steady position) on an archaeological site has been a challenge. “This is why most deep-sea archaeo- logical operations have been limited to documentation, sampling, and digging trial trenches," explains Marek E. Jasinski of the Norwegian University of Science and Technology in Trondheim, pointing to recent ROV sur— veys in the Black Sea and the eastern Mediterranean by Ballard’s Institute for Exploration, and an ongoing survey in Greece by MIT and the Woods Hole Oceano- graphic Institute. “All groups working on deep-sea excavation arrived at the same conclusion—that the best way forward was an ROV attached to a frame,” says Brendan Foley of Woods Hole. While a frame set over an archaeological site would prevent the robot from accidentally coming into contact with fragile artifacts, and allow archaeologists to maneu- ver the ROV with more precision, the cost of deveIOping and testing the new technology was prohibitive for aca- demic researchers. But then, in 2003, Jasinski and his colleague, Fredrik S¢reide, had a magnificent stroke of luck. collaborating on deep-sea survey and excavation S ince the early 19905, Soreide and Jasinski have been technology. So when Norsk Hydro, operator for the inn ANNUAL EDITIONS development phase of the enormous Ormen Lange gas field off Norway’s central coast, was required by national law to perform an archaeological survey of the subsea pipeline tracks in waters far too deep for human divers to explore— Sareide and Jasinski’s research team at the university was a natural choice. The survey, performed in 2003 using traditional ROVs with cameras, sonar, and geophysical survey equipment, revealed a historic shipwreck equal in size to the famous Swedish warship Wasa. (The 225ofoot-long vessel sank on its maiden voyage in 1628 and was raised in 1961.) By archaeological standards, the ship was in good con- dition, splayed open on the muddy bottom with most of its deck and upperworks long gone. The timbers of the lower half of the vessel were well preserved in the sedi- ment, with many of them sticking out from the surface. “Most Norwegian wrecks are found based on reports from divers and fishermen. It is rare that archaeologists locate a wreck themselves as in this case." says Spreide, who was the first to spot the remains of the ship. “It looked like someone had partied hard. Wine bottles were scattered everywhere. Soon we saw more objects: china, ceramics. I realized that it was an historic wreck buried in the mud, probably dating back to the second half of the eighteenth century. That was a good day,” S¢reide recalls. In the Norsk Hydro boardroom, the response was less enthusiastic. Norwegian heritage laws require Hydro to preserve national heritage threatened by construction at their own cost, and the extreme underwater topography made it impossible for Hydro to choose an alternative track for its pipeline from the offshore gas field to a pro- cessing plant at Nyhamna. J asinski, Soreide, and the rest of their nine-person scientific team were put in charge of excavating the site ahead of the pipeline construction, at a calculated cost of about 40 million Norwegian kroner—or $5.6 million. (This was not even the biggest archaeological project associated with the Ormen Lange gas field. Norsk Hydro had already paid about $9.8 million to excavate Stone Age settlements on the site of a natural gas-treat- ment facility on the island of Gossa—the most expensive excavation in Norwegian history.) “One of the major obstacles for us and other scientists trying to solve these issues has been funding," says Jasin- ski. “Receiving the kind of money we did is almost unheard of in the world of marine archaeology.” Where other ROV researchers have scratched the surface, Jasinski says the Norwegian team got “the resources, time, and stamina" to go deep. literally and figuratively, and achieve what has never been done before: the world's first deep-sea scien- tific excavation of a shipwreck. 100 it top of the bountiful resources available to the O archaeologists. the condition of the shipwreck itself, lying only some 600 yards off the coast of what was once one of Norway’s busiest fishing villages, provided a unique opportunity. “Most ships wrecked along the coast of Norway were smashed to pieces. This ship seems to have sunk intact," says Sareide. In the eighteenth century, up to 500 boats fished the surrounding waters of the village of Bud. Myths or stories about shipwrecks normally survive for centuries in the local community. But nobody in the area knows anything about this particular wreck. “The lack of handed-down knowledge is very unusual,” confirms Jasinski. “We got more information about the Pontiac we found dumped close to the site than we got about the wreck itself," says Sareide with a laugh referring to a car dumped off the coast in 1963. The ship’s identity might be a mystery, but nobody questions how a ship and its crew could meet such a cruel end in these waters. The strait off Bud was a point of no return for ships venturing into the treacherous waters of Hustadvika—one of Norway's most notorious coastal waters. “You could hardly find a more classic site for ship- wrecks in Norwegian waters,” Jasinski and Spreide wrote in their project description. Even on a quiet summer day you can feel that nature rules in this area. The sun is shin- ing, the wind is slight, but the current makes the sea boil between the islets. Norsk Hydro was required to have the team excavate just the stern area of the ship—the only area that would be disturbed by pipeline construction. (To attempt to excavate the entire ship at that depth would take several years and tens or even hundreds of millions of dollars). The excava- tion area was mapped and surveyed by ROV and then the university team worked with ROV manufacturer Sperre AS to design a 1,000-square-foot steel frame to be sus- pended above the site. The ROV would be sent down from the research vessel to the site, where it would dock on a rolling bar inside the frame, allowing it to sit only inches above the excavation site. In May 2005, the scientists were ready to start. After some initial technical hiccups, the ROV and frame worked beautifully. allowing precise remote excavation that could extract a maximum amount of data from the sea floor. Advanced sensors transmitted data to the surface—the precise size and location of each artifact, and their relation to each other. Digital images provided the archaeologists with visual information on the in situ artifacts and their environment. Dredges carefully removed sediment and organic remains, while small suc- tion devices and hydraulic arms excavated artifacts with the sensitivity of a fingertip and brush. Preliminary investigations uncovered artifacts from seven different countries. None of them gave any clues to g; ..—.x.::i‘a\'\_‘: "I '- the identity of the ship, or why it met its destiny in these waters. “We are fairly certain we are dealing with a trade ship from the mid to late eighteenth century," Jasinski said as he started his investigations of the recovered material last autumn. The archaeologists found parts of the wooden hull rela- tively intact in the mud. The size and shape was consistent with a trade ship of Western European design. More than 100 wine bottles found on the wreck pointed to the same conclusion. Wine was an important trade item throughout Europe and was also extensively used when crews bar- tered with the locals. “We also found luxurious Chinese porcelain, far too extravagant to have been used in the ship’s mess. The same goes for the three compasses and two octants of uncertain nationality. It was highly unusual to carry more than one set of expensive navigation equipment, unless it was for trade,” says Jasinski. The archaeologists looked east as they continued their study of the more than 500 recovered objects, organic material, and piles of archive material. Russian coins, a Russian flour sack, and buckwheat, a Russian staple. pointed toward Russia, even if the ship’s design was West- ern European. “In his youth Tsar Peter the Great went incognito to Europe to study shipbuilding and work as a car- penter. When he became tsar he forbade traditional Russian shipbuilding. Only Western European con- structions were allowed, where the wooden hull was nailed rather than stitched together. This ship might be a result of his policies,” Jasinski speculated early in the investigation. Despite thousands of objects scattered on the seabed off Bud, huge parts of the cargo were missing. “These ships carried several tons of merchandise. The ship might have been empty on a return voyage, or the cargo was organic—such as salt or flour—and long ago dissolved in the seawater," he added. But now, seawater," he added. But now, the analysis of the pottery has recently been completed, and J asinski may have to drop his theory that the vessel was a Russian ship on its return voyage from Europe. While the bulk of ceramics are German, English, and Chinese, there is also pottery with origins in Spain, the Netherlands, and Southeast Asia. “The English stoneware does not have traces of use, and was probably part of the cargo. The ceramic pots from Southeast Asia, on the other hand, seem to have been in use on board,” says Jasinski. Such evidence leads him to believe this may be a Dutch merchant ship, due to the presence of Dutch colonies in Southeast Asia at the time. “Bearing in mind that the Dutch at this time were deeply involved in trade with northern Russia, the find strength- ens another hypothesis—that we are dealing with a Dutch 101 Article 20. Digging Deep trade ship on its outbound journey to Russia, rather than a Russian ship on its way home from Europe," he adds. Much of the material has yet to be analyzed, such as strange insects recovered from the wreck, which biolo- gists have not been able to identify. It may take months, even years, before the true identity of the ship is uncovered. In the meantime, the artifacts are being studied, conserved, and stored at the university’s Museum of Natural History and Technology (Vitenskaps- museet) in Trondheim. M the technological key to unlock their own deep-sea mysteries. The Russian Academy of Science and research organizations collaborating with the largest Russian gas company, Gazprom, wish to use the Norwegian technology for similar purposes in Russia: preserving cultural heritage sites in conflict with pipeline tracks. The Trondheim team is also talking with Greek authorities about using their robotic excavation technol- ogy on ancient shipwrecks in the Aegean. Woods Hole archaeologist Foley notes that it is not necessarily the technology that has changed the face of maritime archaeology, stressing that it was more the will and ability to bring these technologies to bear. He attri- butes the uniqueness of the Norwegian project to the way a wide range of resources and sciences came together— how engineers, archaeologists, and geologists from the universities worked together with the oil industry and the state to make it happen. “It is rare to see a government recognize the value of shipwrecks and other underwater cultural resources to such an extent,” comments Foley. He also does not expect that the advanced deep-sea excava- tion technology will become a regular household appli- ance with most marine archaeologists. Because of the high costs involved, only the most precious of wrecks will get a visit from “robot-archaeologists” looking to do a full-blown excavation. “The financial barrier will actu- ally help protect wrecks. As any first year archaeology student will learn, excavations are by nature intrusive,” says Foley. “Only when the site is very compelling and important will we excavate.” This summer, Jasinski and Spreide will join up with a team from Texas A&M University to work on a nine- teenth-century wreck located in a pipeline track in the Gulf of Mexico. “However, the task we have been given is different," explains Sareide. “The depth is 4,000 feet and we will not conduct a full excavation, but only collect visible artifacts and document the site." For this challenge, the team has decided to forego the frame, and instead will any countries are now looking to Norway for r_____________ ANNUAL EDITIONS give the ROV legs that fold out like a spider and enable it to “sit” on top of the shipwreck and do the work. “The project in Bud removed the last technological bar- rier for archaeological excavations at great depths," says Jasinski. But he points out that now that true excavation by remote control has been achieved, there is a bigger hurdle for the archaeological establishment to overcome. - .e'qmua.'m.. Jenna‘sng ut-«Ir - :‘qaau' ‘mu-JN. - p: 45* m f .. 4 '“I'TT‘” .- "‘ FromArchaeafagy. May/June 2006. Copyright 0 2006 by Marianne Alfsen/Felix Features. Reprinted by permission of the author. “Marine archaeologists must get used to not having direct, physical contact with the cultural layers and artifacts. But there is no methodological difference between remote control and a more hands-on approach.“ MARIANNE ALI-SEN is a Norwegian-based freelance journalist - u. p..- . mt.- ‘m. we're-4:. wrimwrfiv. In mam r I 102 ...
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