Deep-Sea Hydrothermal Vents and New Life-Forms Are Discovered Summary

  • Last updated on November 10, 2022

John B. Corliss and Robert Duane Ballard discovered deep-sea hot springs and collected previously unknown life-forms uniquely adapted to exploit these submarine oases.

Summary of Event

Coincidence and science often work together. Some of the truly great scientific discoveries have been made when researchers stumbled onto a new insight or fact while they were working toward an unrelated goal. A group of previously unknown life-forms in the deep sea were discovered by just this sort of serendipity, or happy coincidence. Deep-sea hydrothermal vents[Deep sea hydrothermal vents] Hydrothermal vents Marine geology [kw]Deep-Sea Hydrothermal Vents and New Life-Forms Are Discovered (1977) [kw]Hydrothermal Vents and New Life-Forms Are Discovered, Deep-Sea (1977) [kw]Vents and New Life-Forms Are Discovered, Deep-Sea Hydrothermal (1977) [kw]Life-Forms Are Discovered, Deep-Sea Hydrothermal Vents and New (1977) [kw]Discovered, Deep-Sea Hydrothermal Vents and New Life-Forms Are (1977) Deep-sea hydrothermal vents[Deep sea hydrothermal vents] Hydrothermal vents Marine geology [g]South America;1977: Deep-Sea Hydrothermal Vents and New Life-Forms Are Discovered[02660] [g]Ecuador;1977: Deep-Sea Hydrothermal Vents and New Life-Forms Are Discovered[02660] [c]Earth science;1977: Deep-Sea Hydrothermal Vents and New Life-Forms Are Discovered[02660] [c]Biology;1977: Deep-Sea Hydrothermal Vents and New Life-Forms Are Discovered[02660] [c]Science and technology;1977: Deep-Sea Hydrothermal Vents and New Life-Forms Are Discovered[02660] Ballard, Robert D. Corliss, John B. Edmond, John M.

Earth scientists’ idea of how the Earth works changed dramatically in the mid-1960’s, when the theories of seafloor spreading Seafloor spreading and plate tectonics Plate tectonics began to make sense to many scientists. The Earth’s surface is made up of a number of rigid plates, which move away from each other along spreading centers. These centers are located mostly in the major ocean basins; for example, one of them stretches down the length of the Atlantic Ocean. A spreading center looks like a long valley running between a matching pair of deep-sea mountain ridges. Midoceanic Ridge At their outer edges, the Earth’s plates collide with one another; these edges are called “convergent boundaries.” Mountains and active volcanoes Volcanoes often form along these boundaries; the Andes Mountains of South America are an example.

A black smoker hydrothermal vent in the Atlantic Ocean.

(National Oceanic and Atmospheric Administration)

Long ago, earth scientists understood that the force needed to push or pull these plates across the Earth’s surface must be phenomenal. According to the theories, circulation “convection cells” Convection cells (Earth’s mantle) of molten rock rise from deep in the Earth toward the surface (at a spreading center). The molten rock makes cracks in the plate and then forces its way into the cracks. The older, rigid rocks on either side of the cracks are pushed away from the central valley. New rock is continually being formed in the central valley, while old rocks are pushed aside, and everything on the plates on either side of the spreading center moves away from the ridge. This process takes millions of years.

Earth scientists realized that the concentration of molten rock in the central valleys should heat the water in the cracks between the rocks in the valley floor. Some thought there might be hot springs similar to those in Yellowstone National Park deep in the ocean.

In 1977, a group of oceanographers went to an area of the Pacific Ocean near the Galápagos Islands Galápagos Islands to search for hydrothermal (hot water) springs. The team towed a remotely operated camera and a sled carrying other instruments behind their ship, the deep submersible Alvin. Alvin (submersible) The sled carried temperature sensors that could detect any slight increase in water temperature at the ocean floor.

Chimneys of iron oxide on Loihi volcano, Hawaii.

(National Oceanic and Atmospheric Administration)

The team included Robert Duane Ballard, who worked at the Woods Hole Oceanographic Institute near Boston. He had already used Alvin and the instrument sled to study other ridge systems in the ocean. John B. Corliss of Oregon State University and John M. Edmond of the Massachusetts Institute of Technology were also part of the team, along with marine geologists and other oceanographers.

The remote instruments did detect some temperature variations, and photographs showed that there tended to be large clam shells in places where the temperature was different from normal. The scientists brought Alvin closer to investigate. At the bottom, more than 2,500 meters below the ocean’s surface, they found clear evidence of hot springs. In fact, the water near the rocky bottom was shimmering because of the difference in temperature between the normal bottom water and the water that came out of cracks on the seafloor. The scientists also noticed that many of the rock surfaces in these areas were dusted lightly with a white material.

The researchers decided that the hot water coming out of the rocks must be carrying minerals that remained dissolved in hot water but “froze” once the hot water began mixing with the very cold bottom water. In a few places, the hot water was coming out in a concentrated jet so that as the minerals solidified, they formed a hollow chimney. As a result, some of the hydrothermal areas looked like factories with smokestacks (and were nicknamed “black smokers”).

Around the vents, the scientists discovered fascinating biological communities that included gigantic clams, tube worms, and crabs, as well as some organisms that were new to science. Investigating further, the researchers discovered some inactive vents that were surrounded by remains of similar creatures. This made it clear that the organisms were finding their nourishment in the environment of the vents.

Most of what is known about biological communities comes from environments on or near the Earth’s surface, where the Sun provides energy and where the photosynthesis of green plants is the final source of most nutrients. In the hydrothermal vent communities on the deep-sea floor, however, scientists had come upon an ecosystem whose basic food chain was a mystery.

Water samples were taken from near the vent and analyzed; they proved to contain high concentrations of a type of dissolved sulfur called “sulfide.” When the water was filtered and the filters were examined, chemists found large quantities of a kind of bacteria that use dissolved sulfide as the basis of their biochemistry. When clams and worms from these areas were examined, they were found to contain this kind of bacteria.

The researchers concluded that in this deep-sea world without sunlight, there are thriving communities that use the Earth’s internal heat as their basic energy source. The food chain in these communities is based on chemicals leached out of the heated rocks and carried up on water jets to the seafloor surface, where bacterial colonies live. It seems that the vents are not permanent (they may last only thirty or forty years), and when they no longer supply the sulfide-rich water, the communities collapse.

Significance

After the hydrothermal vents and deep-sea communities were discovered near the Galápagos Islands, researchers began searching around the world for similar deep-sea vent systems. The original research team had not included a biologist, so the geologists on the team found themselves trying to answer the many questions that marine biologists in different parts of the world were asking. Scientists have continued to try to understand how the organisms in the deep sea find their way to new hot-water vents to form communities. Deep-sea hydrothermal vents[Deep sea hydrothermal vents] Hydrothermal vents Marine geology

Further Reading
  • citation-type="booksimple"

    xlink:type="simple">Ballard, Robert D. The Eternal Darkness: A Personal History of Deep-Sea Exploration. Princeton, N.J.: Princeton University Press, 2000. In this memoir of deep-sea exploration, Ballard relates the stories of the first deep-sea dives and his team’s discovery of the Titanic and hydrothermal vents.
  • citation-type="booksimple"

    xlink:type="simple">_______. Exploring Our Living Planet. Washington, D.C.: National Geographic Society, 1983. This is a well-written and well-illustrated book devoted to exploring aspects of the revolution in earth science spawned by plate tectonics. Ballard provides an in-person account of discoveries made during dives in Alvin, including the dives in the Galápagos Rift that led to discovery of the hydrothermal vents. There is an excellent index and an adequate bibliography.
  • citation-type="booksimple"

    xlink:type="simple">Corliss, John B., et al. “Submarine Thermal Springs on the Galápagos Rift.” Science 203 (March 16, 1979): 1073-1083. This is a feature summary article that was coauthored by the members of the research team. Although the article is written in a scholarly style, the sense of excitement over the discovery of the new communities comes through, especially through the use of photographs. The article contains some technical data and an authoritative bibliography that college-level readers should find useful.
  • citation-type="booksimple"

    xlink:type="simple">Francheteau, Jean. “The Oceanic Crust.” Scientific American 249 (September, 1983): 114-129. Well-written illustrated article is part of a special issue of Scientific American devoted to summarizing the knowledge of Earth in the light of plate tectonics. Good source of information on the oceanic crust, which underlies and is the foundation for all submarine hydrothermal vents. Briefly touches on the phenomenon of hydrothermal vents.
  • citation-type="booksimple"

    xlink:type="simple">Jones, Meredith L., ed. Hydrothermal Vents of the Eastern Pacific: An Overview. Vienna, Va.: INFAX, 1985. Collection of papers resulting from a conference held in Philadelphia to summarize the biological data to that point. The articles tend to be highly technical but they contain a wealth of information. Profusely, although technically, illustrated. Each article contains an extensive bibliography. Introduction provides a quick history of major research events leading up to the conference.
  • citation-type="booksimple"

    xlink:type="simple">Macdonald, Ken C., and Bruce P. Luyendyk. “The Crest of the East Pacific Rise.” Scientific American 244 (May, 1981): 100-116. An excellent article by members of the multinational research team that explored the hydrothermal vents of the northern East Pacific Rise near the Gulf of California. As is usual for a Scientific American article, the text is not too technical and is complemented by excellent photographs and illustrations. A bibliography is included.
  • citation-type="booksimple"

    xlink:type="simple">Van Dover, Cindy Lee. The Ecology of Deep-Sea Hydrothermal Vents. Princeton, N.J.: Princeton University Press, 2000. Author brings years of experience to the work, intended for professionals, students, and lay readers. Two hundred illustrations.

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