1998 Year of the Ocean The Legendary Ocean — ^The Unexplored Frontier 



TECHNOLOGY FOR DISCOVERY 



Exploring the Deep Sea 



Humans first explored the ocean by directly observing it or by placing samplers and 

 instruments into the sea from their ships. These techniques were limited by the relatively shallow 

 depths then attainable by humans and the relative opaqueness of the sea. Light is rapidly 

 absorbed by sea water, making visibility with conventional techniques virtually impossible 

 beyond shallow depths. Sunlight doesn't penetrate below 300 meters, and relatively few places in 

 the ocean have visibility greater than 30 meters. Thus, observations from the surface are severely 

 limited as are observations by divers alone. In recent years, however, capabilities for ocean 

 exploration have been greatly enhanced by major technological developments that enable seeing 

 far beneath the waves to the seafloor itself 



Although there had been attempts even in antiquity to work underwater, humans had 

 never been able to penetrate very far into the depths until the 1930s. It was then that William 

 Beebe, an American ichthyologist, succeeded in reaching a depth of 1 ,000 meters in his 

 "bathysphere," and providing exciting reports (by live radio broadcast) of life at those depths. 

 Although there were many limitations to his diving platform, Beebe was overwhelmed by the 

 chance to observe marine life in its own environment. A quarter century later, the bathyscaphe 

 Trieste took two men to a depth of 35,800 ft, the deepest spot in the ocean, the Mariana Trench 

 near Guam, in the western Pacific. Although the Trieste lacked manipulators or samplers, it 

 allowed unprecedented observations from the water surface down to the benthos (organisms that 

 live on or in the ocean bottom) and provided a tantalizing glimpse of future discoveries. 



Modern Equipment for Undersea Exploration 



Even when wearing diving gear, humans are limited to relatively shallow depths and 

 short periods of submergence. SCUBA (Self-Contained Underwater Breathing Apparatus), 

 invented in 1 943 by French naval engineers Jacques Cousteau and Emile Gagnan, allows 

 excursions to well below 100 feet for significant durations. The ability to live and work 

 underwater has been greatly expanded through advances in diving physiology and technology. 

 Through the use of saturation diving, scientists can live under the sea in "Aquarius," the only 

 undersea habitat devoted to scientific research. (Aquarius is currently located at the base of a 

 South Florida coral reef) Through techniques such as saturation and mixed-gas diving, scientists 

 can extend their underwater depth and time limits. Yet, while SCUBA has allowed millions of 

 people to become undersea explorers, it still only allows humans the ability to spend relatively 

 short times at comparatively shallow depths. 



The development of the occupied research submersible from the late 1950s to the present 

 allows scientists and explorers access to undersea depths of up to 6,500 m (21,326 ft), although 

 most submersibles have much shallower diving capabilities (300 m to 3,000 m). Modern research 

 submersibles generally have manipulators, lighting, cameras, and sensors allowing detailed 

 observations and experiments. Among the most notable submersible discoveries have been the 



L-5 



