A recent study published in Nature Geoscience has unveiled that the river network surrounding Mount Everest has contributed to its elevation, causing the world’s tallest mountain to rise between 15 and 50 meters over the past 89,000 years. This research sheds light on the evolution of the Himalayas and the influence of river systems on the region’s geology.
Standing at 8,849 meters, Mount Everest—known as Chomolungma in Tibetan and Sagarmāthā in Nepali—dominates the Himalayan landscape, towering approximately 250 meters above the next highest peak. Interestingly, while Everest is considerably taller than its neighboring peaks—K2, Kangchenjunga, and Lhotse—these mountains differ by only about 120 meters.
The study, conducted by researchers at University College London (UCL), found that Mount Everest is currently about 15 to 50 meters taller due to uplift caused by the nearby eroding Arun River gorge. This erosion is attributed to the river network approximately 75 kilometers away from Everest, which continues to sculpt the landscape. The ongoing erosion allows the mountain to rise by about 2 millimeters each year.
The phenomenon, referred to as “isostatic rebound,” occurs when a section of the Earth’s crust loses mass due to erosion, leading to an upward flexing effect as the underlying mantle exerts greater pressure than the downward force of gravity. Although this process is gradual, it can significantly affect the Earth’s surface over geological time.
The Arun River, originating in Tibet as Phung Chu, is part of the Kosi river network and flows into India through Bihar. The study notes that the Arun River, now situated to the east of Mount Everest, has carved a substantial gorge over millennia, washing away billions of tons of earth and sediment.
Co-author Dr. Jin-Gen Dai from the China University of Geosciences highlighted the unique topography of the Everest region, where the Arun River flows eastward at high altitudes before turning south as the Kosi River, indicating a complex interplay between geology and the river’s dynamics.
This research underscores the crucial role river systems play in shaping mountain ranges and provides valuable insights into the geological processes that contribute to the ever-changing height of Mount Everest.
