Produced by: BT Desk
The Arun River, flowing near Everest, was "captured" by the Kosi River 89,000 years ago, triggering massive erosion. This rare event is believed to have pushed Everest higher by 50 to 164 feet.
The Arun River has an unusual L-shaped flow, unlike most rivers that resemble tree branches. This odd pattern led researchers to suspect a river capture had occurred, reshaping the landscape.
River capture occurs when a river or stream is diverted from its original course into a nearby river, usually through erosion. This process can drastically alter landscapes, as seen with the Arun River’s diversion.
The river capture caused rapid erosion, carving the Arun Gorge. This erosion lightened the surrounding landmass, leading to the uplift of Mount Everest, which continues to rise today.
At 29,031.69 feet, Everest is 820 feet taller than K2, a surprising anomaly. Researchers discovered that this unexpected height difference is likely due to the ancient river capture event.
GPS data shows Everest is growing at 0.08 inches per year, faster than the typical uplift rate. This growth likely links back to the river capture, which altered the region's geological balance.
Using numerical models, scientists recreated the evolution of the Kosi River system. These simulations matched current topography, helping confirm the river capture and its impact on Everest’s growth.
Scientists plan to study the Arun Gorge and other areas affected by the river capture to refine the timeline. This will provide more accurate data to confirm how the event impacted Mount Everest’s rise.