Mount Everest, the world’s tallest peak, has a secret: its height might be due to a river’s unexpected influence. A new study published in the journal Nature Geoscience reveals that a river roughly 46 miles from Everest underwent a dramatic change around 89,000 years ago. This event, dubbed a ‘river capture,’ involved a river known as the Arun being ‘captured’ by another river, the Kosi.
The Arun River, unlike other rivers, flows in an unusual ‘L’ shape. This peculiar formation hinted at a potential shift in its course, likely due to the capture event. The study utilized numerical models to simulate the evolution of the Kosi River network, which flows through China, Nepal, and India. The models, combined with topographic data, showed a strong correlation with the capture event and the resulting erosion of the Arun River Gorge.
The researchers believe that the creation of this massive gorge led to a loss of landmass, making the surrounding area lighter. This, in turn, caused Everest to spring up, adding an estimated 50 to 164 feet to its height. Interestingly, the study suggests that Everest’s continued growth could be influenced by this ongoing river network adjustment.
The exact cause of the Arun River’s capture remains a mystery. While the study proposes two possibilities—erosion by the Kosi River or a catastrophic flood from a glacial lake—further research is needed to confirm the exact mechanism. This discovery highlights the complex interplay of geological forces in shaping the Earth’s surface, and adds a fascinating new layer to the story of Mount Everest’s towering presence.
