14 DAY TRIAL // According to a new scientific study, it would appear that the renowned Yangtze River, one of China's two most important bodies of flowing water, is considerably older than first estimated. In previous researches, it was determined that the river was about 5 million years old, but new data seem to indicate that those past measurements were off. In fact, they were way off, scientists say, revealing that the true age of the river is 45 million years. They base their new conclusions on careful analysis of the rocks through which the water cut its course, LiveScience reports.
The Yangtze is the third river in the world when considering length, measuring about 6,300 kilometers (3,915 miles) from spring to its delta. In studies carried out in the Three Gorges region, the place where the largest dam in the world is built, it was revealed that the river was only several million years old. The analysis was conducted on layers of sediment at the location, but the team behind the new investigation says that these rocks must have accumulated at the location long after the Gorges were formed. Additional details of the new work are published in the June 3 issue of the esteemed scientific journal Geology.
“The fact that erosion had removed all of the evidence of the old, pre-merger river courses made dating the river particularly difficult. As the Gorges were cut, they acted as a plughole in a giant bathtub, allowing that sediment to be eroded and flushed down into the growing Yangtze River and out into the East China Sea, depositing the sediment in the lowland areas of eastern China,” explains Alexander Densmore, a geology expert at the Durham University, in the UK. He was also a coauthor of the new journal entry. He explains that previous studies could only be correct if the water cut its way through the Gorges at very high speeds. However, this would have involved extremely high incision rates, evidence of which was not recovered from the location.
The river is now one of the most important sources of water for China, helping to support millions of people. It is also home to the Three Gorges Dam, the largest hydroelectric installation in the world. The Dam's reservoir is impressive in size. When filled, it spans about 660 kilometers (410 miles) in length and 1.12 kilometers (0.70 miles) in width, on average. It also contains about 39.3 cubic kilometers (9.4 cubic miles) of water, which it collects from a catchment area of 1,000,000 square kilometers, or about 386,102 square miles. A study published last year in the respected Journal of Geophysical Research shows that the hydroelectric power plant, which is advertised as a green power source, is a living example of the adverse effects that some green technologies can indirectly have on the environment.