Few locations on Earth are as remote as the deep oceans. Although more than 1,500 people have successfully climbed Mount Everest, more than 300 men and women have journeyed into space, and 12 men have walked on the moon, only two people have descended and returned in a single dive to the deepest parts of the ocean, and they spent less than 30 minutes in a cloud of sediment on the ocean, bottom (Exploration, 2003).
The ocean remains one of Earth's last unexplored frontiers. Covering over 70 percent of the surface of the earth, the oceans regulate our weather and climate, sustain a large portion of Earth's biodiversity, and provide humanity with substantial living and nonliving resources. Despite our intimacy with the sea, much of the world's oceans and ocean floor remain unexplored. The National Oceanic and Atmospheric Administration (NOAA) estimates that between 95 and 99 percent of the ocean floor is unexplored. The ocean floor is the last frontier on earth, and explorations will yield discoveries that may shake the very foundations of centuries-old beliefs about the basic nature of the earth itself.
Until recently, the obstacles facing deep-sea exploration were almost insurmountable. Venturing into complete darkness, frigid water, and extremely high pressure made research nearly impossible. The technology of deep-sea exploration has advanced from twine and cannon ball soundings to ocean surveys from space and robotic exploration of the deep ocean floor. Recent advances in manned submersibles and remotely operated vehicles are now making the deep seas more accessible. Technology, fueled by scientific curiosity, has revealed the deep ocean as a dynamic geological environment. The discoveries of intricate ecosystems at mid-ocean volcanic vents and the unexpected diversity of marine life are revolutionizing biological science.
A Brief History of Deep-Sea Exploration
Deep-sea exploration is the investigation of the physical, chemical, and biological conditions at the bottom of the ocean for scientific and commercial purposes. Throughout history, scientists have relied on a number of specialized tools to measure, map, and view the ocean's depths. One of the first instruments used to investigate the ocean floor was the sounding weight. Viking sailors took measurements of the depth of the ocean and samples of seafloor sediments with this device, which consisted of a weight with a hollow bottom attached to a line. Once the weight reached the ocean bottom and collected a sediment sample, the line was hauled back onboard ship and measured by the distance between a sailor's outstretched arms--a 1.83-meter (six foot) unit that was called a fathom, a term still used today for nautical depth.
The depths of the earth's oceans have been investigated with precision only during the past several decades. Compared to other areas of geological and marine research, they still remain a relatively unexplored domain. Modern scientific study of the deep sea can be said to have begun when the French scientist Pierre Simon de Laplace calculated the average depth of the Atlantic Ocean from tidal motions registered on the Brazilian and African coasts. Laplace determined the depth to be 3962 m (13,000 feet), a value proven quite accurate by later sonar sounding readings (Deep-Sea, 2005). The nature of the seafloor was an unrevealed mystery until the mid-nineteenth century; scientists and artists alike envisioned the deep sea as a lifeless liquid of docile water contained by a bowl of static rock. By the late 1860s, however, controversial theories of the origin of life by evolution and the vastness of geologic time (the period of time covering the formation and development of the earth) had created a climate of scientific curiosity and piqued a general interest in marine science. The Royal Society of London thus mounted an ambitious oceanographic expedition to augment a sparse collection of existing marine data that included Charles Darwin's observations during the voyage of the Beagle from 1831-1836. …