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Welcome to the Underwater Archaeology Homepage from UnderwaterArchaeology.com! |
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Deep Sea Exploration Along the coastlines of most large continents is an area of relatively shallow water called the continental shelf, where the sandy bottom is often not more than a few hundred feet deep, often well within the range of recreational and commercial scuba diving.
Beyond this extended area of shallow water, the bottom slopes off from the continents into deeper water (called the continental slope) and then drops off into the deep ocean floor, called the abyssal plane. The abyssal planes are the vast, flat, mostly unexplored areas of the ocean bottom that comprise about 40 percent of the total ocean floor. They typically reach depths of 2,000 to 5,000 meters, or about 7,000 to 18,000 feet deep. It is these vast areas of incredible depth that researchers are just beginning to explore with the new technologies of today! Deep Sea Trenches and The Challenger Deep Oceanic trenches are long, deep, narrow depressions in the ocean floor that are created by the movement of the plates that make up the Earth's crust. The trenches that are formed where these plates push and pull each other apart are the deepest parts of the ocean. Of these trenches, the Challenger Deep is the deepest known point in the ocean. It lies at the southern end of what is known as the Mariana trench, named after the Mariana islands in the pacific ocean. The point known as Challenger Deep gets it's name from the British surveyor ship Challenger II, which originally pin-pointed the location in 1951. Nine years later, the U.S. Navy sent down the Trieste, a manned mini-submersible on a mission to land on the bottom. After a descent of almost 5 hours the Trieste landed on the ocean floor. With 7 miles of ocean over their heads, the crew of two men stayed for twenty minutes, observing fish such as sole and flounder, and then began their three hour ascent. Deep Sea Shipwrecks and Remotely Operated Vehicles At depths of thousands of feet, with the weight of literally miles of ocean overhead, the pressures can be crushing. Until recently, it was not possible for ROV's to descend to the same depths as mini-submersibles. Remotely operated underwater vehicles (ROVs) are underwater robots tethered to ships and then sent down to explore the deep ocean. They are unmanned, and operated by a skilled technical crew from a control room in the vessel on the surface. The operators maneuver them, receive video data, and control mechanical arms of the robot through signals sent through an umbilical cable. Until recent years, ROV's were limited to maximum depths of between 3,000 and 6,000 feet, but recent advancements are now making it possible for researchers to go much deeper. Many experts agree that 90 percent of the world's shipwrecks will be discovered in the next 30 years. Modern ROV's are now in the early stages of mapping out and exploring anomalies found in these vast areas of ocean floor. Hydrothermal Vents in the Deep Sea Hydrothermal vents are like geysers, but found on the floor of the deep ocean. Deep sea hydrothermal vents are found along the mid-ocean ridges and volcanic mountain ranges such as those around the Hawaiian Islands. The vents are created by seawater that seeps down into the cracks created by the earth's crust. The superheated water becomes saturated with minerals and then spews up from the fissures in the seafloor, creating a rising dark colored plum. These vents create fantastic structures of minerals in their wake, and support an entire eco-system of life that live on the energy created by the heat. The study of hydrothermal vents typically falls outside of the purview of archaeologists, and instead involves a multidisciplinary approach between geologists and chemists. Because of the absence of sunlight, the eco-system created around hydrothermal vents is completely unique and one of the startling scientific discoveries of our time. Interesting links for further reading: A Brief History of
Deep Sea Exploration: NOAA Ocean Explorer
Deep Sea Hydrothermal Vents
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Underwater Archaeology Links General Archaeology Links World Travel
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