Historic Dives: Two Deep-Sea Submersibles Exploring Earth’s Inner Space on the Mid-Atlantic Ridge
July 11, 1997
The U.S. deep-diving submersible Alvin, operated by the Woods Hole Oceanographic Institution on Cape Cod, Massachusetts, and the French submersible Nautile are diving today on the Mid-Atlantic Ridge, an undersea mountain range in the middle of the North Atlantic Ocean, in a historic example of international cooperation and exploration of planet Earth. It is believed to be the first time that human-occupied submersibles from two nations have rendezvoused on the deep ocean floor to work in visual sight of each other. At the same time as space scientists explore the distant planet Mars, marine scientists on Earth are exploring areas of the ocean floor never seen before. Their dives may lead to the discovery of new life forms, and scientists on the expedition expect to find new species of animals and to collect bacteria that may play a vital role in biomedical research.
The American and French subs are exploring areas on the Mid-Atlantic Ridge not far from the Azores, where new ocean floor crust is forming, creating the right conditions for the formation of hydrothermal vents full of new species of life, including shrimp, mussels, fish and worms. Sunlight supports plant growth via photosynthesis on land, but since there is no sunlight on the seafloor, deep-sea bacteria at the vents oxidize hydrogen sulfide coming from the earth’s interior in a process known as chemosynthesis, converting carbon dioxide to organic carbon that the shrimp and mussels eat to survive. Today’s dive is at a new vent site named Rainbow which was recently detected by its plume but never explored. Eighteen Alvin dives are planned during the current expedition to depths up to two and one-half miles at vent sites named Lucky Strike, Broken Spur, TAG, and Snake Pit. The French submersible Nautile is working from its support vessel, the 277-foot L’Atalante,operated by the French government agency IFREMER.
The 23-foot Alvin, which carries a pilot and two scientific observers to depths up to 4,500 meters (14,764 feet), and its brand new support ship, the 274-foot Research Vessel Atlantis, are operated by the Woods Hole Oceanographic Institution in Woods Hole, Massachusetts, for the American ocean research community. Alvin which found the first hydrothermal vents in the Pacific in 1977, has made more than 3,100 dives and is considered the world’s most active and productive deep-sea exploration vehicle of the six in existence. The sub routinely makes 150-175 dives per year. The 54-member American expedition, headed by Drs. Robert Vrijenhoek and Richard Lutz of Rutgers University, includes scientists from Rutgers University and the University of Washington in the U.S. and scientists from India, Great Britain and Portugal, as well as the Research Vessel Atlantis and submersible Alvin crews from Woods Hole Oceanographic Institution.
The American expedition began July 5 from the Azores when Research Vessel Atlantis departed Ponta Delgada on a 30-day cruise to explore the eight known hydrothermal vent sites along the Mid-Atlantic Ridge, all discovered since 1985. Scientists diving in Alvin found the first hydrothermal vents in the Pacific Ocean near the Galapagos Islands in 1977 and has since found more than two dozen sites in the Atlantic and Pacific containing some 300 species of animals never known before, including foot-long clams and mussels and red-tipped tube worms that grow in some vent sites up to 10 feet in length. Dramatic black smokers full of minerals, spewing the hottest water even found in the open ocean at close to 400 degrees Celsius (752 degrees Fahrenheit), have been discovered by Alvin at Pacific vent sites.
Alvin Expedition Leader and Chief Pilot Patrick Hickey of Mashpee, Massachusetts, is aboard the French submersible support ship L’Atalante to coordinate the joint diving activities. The Alvin pilots for the two joint dives July 11 and 12 with the French are expected to be Matthew Heintz of Chadds Ford, Pennsylvania, and Robert Lee Williams of Jacksonville, North Carolina.
In 1974 Alvin and the now retired French submersible Archimede , also operated by IFREMER, dove on the Mid-Atlantic Ridge as part of Project FAMOUS (French-American Mid-Ocean Undersea Study), which confirmed the theory of plate tectonics and continental drift. However, the two subs never worked in sight of each other. The two Russian submersible MIRS have worked closely together, but the joint dives July 11 and 12 are believed to be the first time deep-sea subs from two nations have done so.
The Mid-Atlantic Ridge is a part of the Mid-Ocean Ridge, a 46,000-mile long undersea mountain range that circles the earth like the seams on a baseball. Scientists estimate that less than one percent of the entire ridge system has been explored. Both Alvin and Nautile have worked on the ridge before, but rarely in the same location and never before in sight of each other. There are only six human-occupied subs in existence that can dive deeper than 10,000 feet.
Atlantis and Alvin will head south to dive on other vent sites along the Mid-Atlantic Ridge beginning July 13, while the French will remain at the Rainbow site for further studies. Following completion of their vent work, Alvin and Atlantis are scheduled to arrive in Bridgetown, Barbados, August 1. The ship and sub will then travel to the Pacific to begin a two-year diving research program.
For additional information, contact:
Shelley Lauzon, Senior News Officer
Woods Hole Oceanographic Institution, Woods Hole, MA, 02543
508-289-2270
FAX: 508-457-2180
slauzon@whoi.edu