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Deep-sea exploration is the investigation of physical, chemical, and biological conditions on the sea bed, for scientific or commercial purposes. Deep-sea exploration is considered as a relatively recent human activity compared to the other areas of geophysical research, as the depths of the sea have been investigated only during comparatively recent years. The ocean depths still remain as a largely unexplored part of the planet, and form a relatively undiscovered domain. In general, modern scientific Deep-sea exploration can be said to have begun when French scientist Pierre Simon de Laplace investigated the average depth of the Atlantic ocean by observing tidal motions registered on Brazilian and African coasts. He calculated the depth to be 3,962 m (13,000 ft), a value later proven quite accurate by soundings measurement.〔Deep Sea Exploration." World of Earth Science. Ed. K. Lee Lerner and Brenda Wilmoth Lerner. Gale Cengage, 2003. eNotes.com. 2006. 7 Dec, 2009 The first instrument used for deep-sea investigation was the sounding weight, used by British explorer Sir James Clark Ross.〔()〕 With this instrument, he reached a depth of 3,700 m (12,140 ft) in 1840.〔(【引用サイトリンク】title=DEEP-SEA EXPLORATION (2009) )〕 The Challenger expedition used similar instruments called Baillie sounding machines to extract samples from the sea bed.〔(【引用サイトリンク】title=Underwater Exploration - Oceanography )〕 Teleoperated Robotics is one of the safest way to explore deep waters: a remotely operated robot vehicle (ROV) becomes the divers eyes and hands in deep marine environments. Decompression sickness ('the bends') can occur if a diver surfaces too quickly from extreme depths; nitrogen in the blood will come out of solution during rapid ascent, and can cause serious injury or death. Using teleoperated robotics or Atmospheric Diving Suits (ADS), which are human shaped (anthropomorphic) submarine exoskeletons, provide a relatively safe method of exploration, with the disadvantage that the lack of fine motor control limits how much of the environment can be closely examined. Bhargav Gajjar of Vishwa Robotics and Massachusetts Institute of Technology, with funding from the Office of Naval Research of the US Navy, is conducting research into deep-sea manipulators in an effort to create a more sensitive system for deep-sea work. This technological breakthrough is a major milestone in human exploration of the last frontier. In 1960, Jacques Piccard and US Navy Lieutenant Donald Walsh descended in the bathyscaphe Trieste into the Mariana Trench, the deepest part of the world's oceans, to make the deepest dive in history: 10,915 meters (35,810 ft). On 25 March 2012, filmmaker James Cameron descended into the Mariana Trench and, for the first time, is expected to have filmed and sampled the bottom. ==History== Throughout history, scientists have relied on a number of instruments to measure, map, and observe the ocean's depths. One of the first instruments used to examine the seafloor was the sounding weight. Ancient Viking sailors took measurements of sea depth and sampled seafloor sediments with this instrument, which consisted of a lead weight with a hollow bottom attached to a line. Once the weight reached the sea bottom and collected a sample of the seabed, the line was hauled back on board ship and measured in fathom. Cornelius Drebbel, a Dutch architect, is generally given credit for construction of the first submarine. His submersible boat consisted of a wooden frame sheathed in animal skin. Oars, with its openings were sealed with tight-fitting leather flaps, extended out the sides to propel the craft through the water, at depths up to 4.6 metres (15 ft). Drebel tested his submarine in the Thames River in England in sometime between 1620 and 1624. It is believed that King James I enjoyed a short ride in the craft. However, the nature of the deep ocean remained an unrevealed mystery until the mid-19th century. Scientists and artists alike imagined the deep sea as a lifeless soup of placid water. French author Jules Verne, who helped pioneer the science-fiction genre, portrayed the deep ocean as contained in a bowl of static rock in his “Twenty Thousand Leagues under the Sea”. By the late 1860s, controversial modern scientific theories, the origin of life by evolution and the enormity of geologic time had created a foundation of scientific curiosity and provoked a rising interest in marine exploration. The Royal Society of England thus initiated an ambitious oceanographic mission to expand a scarce collection of existing marine data that included Charles Darwin's observations during the voyage of the HMS Beagle (1831–1836), a bathymetric chart created by U.S. Navy Lt. Matthew Maury to aid installation of the first trans-continent telegraph cables in 1858, and a few examples of deep marine creatures.〔"Deep Sea Exploration." World of Earth Science. Ed. K. Lee Lerner and Brenda Wilmoth Lerner. Gale Cengage, 2003. eNotes.com. 2006. 9 Dec, 2009 From 1872 to 1876, a landmark ocean study was carried out by British scientists aboard HMS Challenger, a sailing vessel that was redesigned into a laboratory ship. The HMS Challenger expedition covered 127,653 km (68,890 nautical miles), and shipboard scientists collected hundreds of samples, hydrographic measurements, and specimens of marine life. They are also credited with providing the first real view of major seafloor features such as the deep ocean basins. They discovered more than 4,700 new species of marine life, including deep-sea organisms. Deep-sea exploration advanced considerably in the 1900s thanks to a series of technological inventions, ranging from sonar system to detect the presence of objects underwater through the use of sound to manned deep-diving submersibles such as DSV Alvin. Operated by the Woods Hole Oceanographic Institution, Alvin is designed to carry a crew of three people to depths of 4,000 meters (13,124 ft). The submarine is equipped with lights, cameras, computers, and highly maneuverable robotic arms for collecting samples in the darkness of the ocean's depths. However, the voyage to the ocean bottom is still a challenging experience. Scientists are working to find ways to study this extreme environment from the shipboard. With more sophisticated use of fiber optics, satellites, and remote-control robots, scientists one day may explore the deep sea from a computer screen on the deck rather than out of a porthole.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Deep-sea exploration」の詳細全文を読む スポンサード リンク
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