Tools and Engineering A Special Ship Scientists on the black smoker expedition will travel on the Pacific Ocean aboard the research ship the Atlantis in order to reach the Endeavor segment of the midocean ridge. The Atlantis is one of several ships available to the international community for scientific research in the world's oceans. It is operated by the Woods Hole Oceanographic Institution. The Atlantis launches, monitors, and communicates with the submersible ALVIN, which always travels with the Atlantis. Furthermore, the Atlantis can launch the ROV Jason. The Jason and ALVIN are needed for research and sample collection. The Atlantis is also equipped with a dynamic positioning system. This system keeps the ship steady and in one place while precise measurements are made using the ROV and submersible on the seafloor. In addition to being well-suited for the research tasks, the Atlantis was selected for this expedition because it is in the eastern Pacific at this time and is available for the black smoker expedition. DIVING DOWN TO THE ENDEAVOR RIDGE ON THE MIDOCEAN RIDGE? Deep-Sea Submersibles: The ALVIN scientists travel down to the ocean floor using a submersible to make firsthand observations of the sulfide structures and the life-forms that live on them and to collect samples. Deep-sea submersibles like the ALVIN are special because they can go to greater depths than ordinary submarines (depths greater than 2,000 meters). The ALVIN is the deep-sea research submersible owned by the United States government. It can carry three passengers and dives to a maximum depth of 4,000 meters. Conditions inside the ALVIN are very cramped. Three people, usually two scientists and a pilot, can barely fit. The scientists and pilot sit on the floor and peer out of three small portholes made of very thick glass. Sunlight penetrates through only the upper 1,000 meters of the ocean. The ocean below this depth is therefore totally dark. The ALVIN carries spotlights to provide light for navigation and observations, and digital cameras for photography and videography. The ALVIN has mechanical arms and a basket for storing samples. Scientists can use ALVIN's mechanical arms to collect pieces of sulfide structures, ocean floor rocks, life-forms, and samples of water, which are then stored in the basket. A total dive might last eight to ten hours, including two to four hours of travel time down and up, and four to six hours of "bottom" time‹time to explore the ocean floor and collect samples. The ALVIN is not big enough to have a bathroom. If required (and usually ALVIN passengers try very hard not to need it!) bottles are used instead. The international research community has a number of deep-sea submersibles. These submersibles differ mainly in their depth capabilities. There are several criteria in the selection of a research vehicle: € ability to perform research € cost efficiency for the depth of the dive € equipment is in the region and won't take weeks to reach you € equipment is available for use Submersible Owned By Depth Capability Shinkai 2000 Japan 2000 meters ALVIN United States 4000 meters Nautile France 6000 meters Shinkai 6500 Japan 6500 meters Cyana France 3000 meters Griffon France 600 meters Links: Shinkai 2000: http://www.jamstec.go.jp/jamstec/2k.html ALVIN: www.marine.whoi.edu/ships/alvin/alvin.htm Nautile: http://www.ifremer.fr/boc/engins/naut_uk.htm Shinkai 6500: http://www.jamstec.go.jp/jamstec/6k.html Cyana: http://www.ifremer.fr/boc/engins/cyana_uk.htm Griffon: http://www.ifremer.fr/boc/engins/griff_uk.htm Remotely Operated Vehicles (ROVs): The Jason/Medea Unlike submersibles, which carry scientists to the ocean floor, ROVs are robotic. But the ROV still requires people for its operation because it is tethered to the ship above and is controlled by scientists and engineers on board the ship through the tethering cable. ROVs enable high-quality scientific observation and data collection on the deep, remote ocean floor without placing people on the ocean floor. Like submersibles, ROVs include high-quality still and video cameras, temperature sensors, mechanical arms, and baskets for sample collection. Jason, the main research tool on this expedition, works with another vehicle called Medea. Together they function as a dual-vehicle ROV. Jason has the ability to obtain highly precise imaging and data collection, while Medea has survey capabilities and serves as Jason's base. Jason is linked by a 100-meter cable to Medea; Medea is then linked by a much longer cable to the ship overhead. Both Medea and Jason are designed to operate to a maximum depth of 6,000 meters and they can be operated from a variety of research or commercial vessels. Jason was used to explore the Titanic and is a key feature of the Jason Project. The Jason/Medea ROV is equipped with digital cameras from Mystic Aquarium to document the black smoker sulfide structures and the life-forms living on the structures, temperature probes to obtain temperature data, and a high-precision manipulator (arm) and small basket for taking and storing samples. Larger samples can be taken by the Jason and loaded either onto Medea or onto a separate sample platform. A key advantage of this dual-vehicle ROV is that Medea and Jason can provide light for each other's operations. ROVs Owned By Depth Capability Jason/Medea United States 6000 meters Victor 6000 France 6000 meters Kaiko Japan 6000 meters © 1997, American Museum of Natural History