Ballard Team Has High Hopes for Deep-Water Robot
for National Geographic News
|July 16, 2003|
Undersea explorer Robert Ballard has likened the ocean floor to a vast museum holding an unrivaled archaeological record of human history. This summer, as Ballard and a team of scientists embark on a 40-day expedtion to the Black Sea and Mediterranean, they will bring an exciting new tool for exploring this underwater realm.
Hercules, an innovative underwater remotely operated vehicle (ROV) equipped with mechanical arms, fingers, and a variety of tools, will enable Ballard and his team to conduct the first archaeological excavations of shipwrecks and archaeological sites in the deep sea.
The expedition team will revisit recently discovered archaeological sites in the Black Sea and Mediterranean. With Hercules in tow, the team hopes to conduct the first meaningful excavations of these sites.
The effort may yield more tantalizing clues about life in the Black Sea and Mediterranean regions during the age of ancient Greece. It could also turn up further evidence to support the Black Sea flood theory. The theory holds that following the last ice age, rising sea levels in the Mediterranean breached a natural dam that separated the two bodies of water, an event that resulted in a catastrophic flood that raised the Black Sea to its present levels.
Ballard, a National Geographic Society Explorer-in-Residence and president of the Institute for Exploration (IFE) at Connecticut's Mystic Aquarium, and his team have relied on a pair of undersea vehicles, ARGUS and Little Hercules, on past expeditions.
The vehicles, designed to work in tandem, remain connected to the mother ship via an armor-plated fiber-optic cable laced with electrical wires. Pilots can maneuver the vehicles using remotely controlled thrusters.
Little Hercules' primary mission is to shoot high-definition video of underwater objects, artifacts, or shipwrecksallowing ship-based researchers to virtuallyand safelyexplore the ocean depths. The ROV's pilot uses four thrusters to maneuver Little Hercules freely on the 100-foot (30-meter) tether that connects it to ARGUS.
"All the vehicles IFE has had up to now are for survey and imaging," explained chief engineer Jim Newman. The president of Woods Hole Marine Systems Inc., in Woods Hole, Massachusetts, Newman spearheaded the efforts to build Hercules and numerous other ROVs used by Ballard.
"ARGUS and Little Herc feature camera systems that can go in and investigate sonar anomalies. With sonar, you just know that there's something weird there [on the ocean floor]. It could be a rock, a modern shipwreck, or something of real interest," he said. "The only way to determine that is to go in and get video. That's what Little Herc was built for."
But video is no longer enough. The time has come for the team to dig a little deeperliterally. Hercules, developed by IFE (with excavation tools developed by the Deep Submergence Laboratory at Woods Hole Oceanographic Institution), is specially designed for excavating and recovering artifacts from underwater archaeological sites and shipwrecks that rest at depths up to 3,000 meters (9,840 feet).
"You can learn a fair amount [with video]. But at some point you want to reach in there, start digging, and see what's there," Newman told National Geographic News. "This is an excavation vehicle, designed to perform the same kind of tasks that a land-based archaeologist does with his hands and tools."
A Better Tool
To accomplish this goal, Hercules is outfitted with two mechanical arms that can lift, push, and grab. The left arm is more powerful. The right is designed for more delicate, intricate work. Each arm has a pair of stainless steel "fingers."
The vehicle employs a variety of archaeological tools. Newman explained: "The primary tool for moving sediment is a jetting system, a fairly benign little jet and a suction system to try to contain the sedimentbecause you won't be able to see anything unless you do something about that. We'll also have brushes and some other tools. It's all very new technology, and it's experimental."
The vehicle is also equipped with visual and acoustic sensors and high-definition television systems.
Newman's team has put Hercules together in little over a year. His biggest concern: integrating all of the features so that Hercules can function properly. "It's a brand new system so there are thousands of things that need to work, and not everything has worked together yet," he said.
Hercules's mission in robotic life is to dig into shipwrecks, said Newman. "To pull off the first layer of the amphora and see what's underneath."
With that ability comes a scientific responsibility that the team embraces. "Anything we do beyond visual [inspection does] damage to the site. And that's a big deal," said Newman. "We will document the site before we touch anything, move the surface artifacts off the site proper, and document each one [in the process] so we could virtually recreate the site. Then we'll start digging and find out what's below."
The effort mimics the work of underwater archaeologists diving in shallower water, but will be unlike anything ever attempted at such depths.
"We're pioneering a whole new area of archaeology in terms of deep ocean work that truly [meets] archaeological standardssupportable in an academic vein," he continued. "This will be the first time to my knowledge that anybody has tried to do more than just pick up objects that are already exposed on the bottom [of the ocean floor]."
Hercules recently arrived in Malta, where this summer's expedition will soon begin aboard the Woods Hole research ship R/V Knorr. The vessel has been good to Ballard. It was aboard this ship that he made the 1985 discovery of the RMS Titanic.
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