Quantum technique used to determine age of modern Yellow River: study

BEIJING, Oct. 27 (Xinhua) -- Scientists grappling with dating the age of the modern Yellow River, China's second-longest river, the "mother river" of the nation and the cradle of Chinese civilization, have made a breakthrough using a quantum technique.

The modern water system of the Yellow River was formed about 1.25 million years ago, according to a study published in the latest edition of Earth and Planetary Science Letters.

The team behind the discovery was led by researchers from the Institute of Geology and Geophysics under the Chinese Academy of Sciences, Beijing Normal University, and University of Science and Technology of China. They dated the geothermal water in Weihe Basin of China, via a combined use of isotopic krypton and chlorine.

The study applied the atom trap trace analysis, a quantum technique, to count at the single atomic level, which allows for extremely sensitive measurement.

The formation of the modern Yellow River drainage had previously been controversial. Hydrologists proposed that the river might have taken its present shape 150,000, 1.2 million or 5 million years ago.

The new results supported the hypothesis that the birth of the modern Yellow River was at about 1 to 1.3 million years ago, a period witnessing the drainage reorganization from the Ancient Sanmen Lake to how the waterway runs today.

The 5,464-km-long Yellow River feeds about 12 percent of China's population, irrigates about 15 percent of arable land, supports 14 percent of national GDP and supplies water to more than 60 cities.