It is located approximately 3,960 meters (13,000 feet) beneath the Amazon River in South America.
The two Brazilian researchers used data from boreholes sunk in the Amazon region by the Brazilian oil company Petrobras, which took temperature readings of these spots for use in new oil and gas fields.
Actually, 241 boreholes were sunk by Petrobas from the 1970s to the 1980s.
The data studied by the researchers show that the movement of the subterranean water is basically vertical at about 2,000 feet (610 meters) below the surface, but changes to being basically horizontal at depths over 2,000 feet.
Dr. Hamza stated, "We have used the term 'river' in a more generic sense than the popular notion.' [BBC News (8/27/2011): 'Subterranean Amazon river 'is not a river'']
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