Nepal, Oct 01 (Alliance News): Thousands of years ago, in the Himalayas, a geological event known as “river piracy” gave an unexpected lift to Mount Everest’s height, according to new research.
Scientists have discovered that around 89,000 years ago, the Kosi River in Nepal captured a tributary of the Arun River.
This event triggered a chain reaction that eroded large portions of the landscape, causing the surrounding Himalayan peaks — including Everest, Lhotse, and Makalu — to rise higher than previously expected.
Mount Everest, standing at 29,031.69 feet (8,848.86 meters) above sea level, was already formed around 40 to 50 million years ago when the India and Eurasian tectonic plates collided.
The newly discovered increase in height, however, resulted from the geological process of isostatic rebound.
As the Kosi River eroded rock from the valleys around Everest, the crust beneath the surrounding peaks compensated for the loss, lifting Everest by as much as 164 feet (50 meters).
The research was published in the journal Nature Geoscience and adds a new layer to our understanding of how rivers can reshape landscapes and contribute to mountain formation.
“The main driver of Everest’s height remains the plate collision, but our discovery adds a new piece to this complex puzzle,” said Jin-Gen Dai, a geology professor at China University of Geosciences and coauthor of the study.
This research also addresses some geological anomalies in the region, such as the unusual course of the Arun River and the particularly high elevations of Everest, Lhotse, and Makalu compared to neighboring peaks.
