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Theocean bottom – a region nearly 2.5 times greater than the total land area ofthe Earth – is a vast frontier that even today is largelyunexplored and uncharted. Until about a century ago, the deep – ocean floor wascompletely inaccessible, hidden beneath waters averaging over3,6000 meters deep. Totally without light and subjected to intense pressureshundreds of times greater than at the Earth*s surface, the deep – ocean bottomis a hostile environment to humans, in some ways as forbidding and remote asthe void of outer space.
Although researchers have takensamples of deep – ocean rocks and sediments for over a century, the firstdetailed global investigation of the ocean bottom did not actually start until1968, with the beginning of the National Science Foundation*s Deep Sea DrillingProject (DSDP). Using techniques first developed for the offshore oil and gasindustry, the DSDP*s drill ship, the Glomar Challenger, was able to maintain asteady position on the ocean*s surface and drill in very deep waters, extractingsamples of sediments and rock from the ocean floor.
The Glomar Challenger completed96 voyages in a 15 – year research program that ended in November 1983. Duringthis time, the vessel logged 600,000 kilometers and took almost 20,000 coresamples of seabed sediments and rocks at 624 drilling sites around the world.The Glomar Challenger*s core samples have allowed geologists to reconstructwhat the planet looked like hundreds of millions of years ago and to calculatewhat it will probably look like millions of years in the future. Today, largelyon the strengthof evidence gathered during the Glomar Challenger*s voyages, nearly all earthscientists agree on the theories of plate tectonics and continental drift thatexplain many of the geological processes that shape the Earth.
The cores of sediment drilled bythe Glomar Challenger have also yielded information critical to understandingthe world*s past climates. Deep – ocean sediments provide a climatic recordstretching back hundreds of millions of years, because theyare largely isolated from the mechanical erosion and the intense chemical andbiological activity that rapidly destroy much land – based evidence of pastclimates. This record has already provided insights into the patterns andcauses of past climatic change – information that may be used to predict futureclimates.
Although researchers have takensamples of deep – ocean rocks and sediments for over a century, the firstdetailed global investigation of the ocean bottom did not actually start until1968, with the beginning of the National Science Foundation*s Deep Sea DrillingProject (DSDP). Using techniques first developed for the offshore oil and gasindustry, the DSDP*s drill ship, the Glomar Challenger, was able to maintain asteady position on the ocean*s surface and drill in very deep waters, extractingsamples of sediments and rock from the ocean floor.
The Glomar Challenger completed96 voyages in a 15 – year research program that ended in November 1983. Duringthis time, the vessel logged 600,000 kilometers and took almost 20,000 coresamples of seabed sediments and rocks at 624 drilling sites around the world.The Glomar Challenger*s core samples have allowed geologists to reconstructwhat the planet looked like hundreds of millions of years ago and to calculatewhat it will probably look like millions of years in the future. Today, largelyon the strengthof evidence gathered during the Glomar Challenger*s voyages, nearly all earthscientists agree on the theories of plate tectonics and continental drift thatexplain many of the geological processes that shape the Earth.
The cores of sediment drilled bythe Glomar Challenger have also yielded information critical to understandingthe world*s past climates. Deep – ocean sediments provide a climatic recordstretching back hundreds of millions of years, because theyare largely isolated from the mechanical erosion and the intense chemical andbiological activity that rapidly destroy much land – based evidence of pastclimates. This record has already provided insights into the patterns andcauses of past climatic change – information that may be used to predict futureclimates.
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