Mount Everest, the world’s highest peak, is even taller than previously thought, thanks to the erosion caused by a river network at its base. A new study by researchers at University College London (UCL) reveals that Mount Everest is 15-50m taller than it would otherwise be, with the Arun river network playing a significant role in its growth.
The study explains that as the Arun river flows through the Himalayas, it erodes rock and soil, reducing the force on the Earth’s crust and causing it to flex and float upward. This phenomenon, known as isostatic rebound, is pushing Mount Everest and other neighboring peaks, such as Lhotse and Makalu, upward at a rate of about 2mm per year.
While plate tectonics from the collision of the Indian and Eurasian plates millions of years ago initially formed the Himalayas, the ongoing erosion from the Arun river network is contributing to the mountains’ continued rise. The researchers suggest that the Arun river gained its erosive power when it captured another river or water body in Tibet 89,000 years ago.
Dr. Xu Han, the lead author of the study, highlights the dynamic nature of the Earth’s surface and how the interaction between river erosion and the Earth’s mantle pressure is boosting Mount Everest’s height. The study, published in Nature Geoscience, sheds light on the complex processes shaping the world’s tallest peaks.
While some geologists acknowledge the plausibility of the study’s findings, there are still uncertainties surrounding the exact impact of river incision and the uplift of surrounding peaks. However, the possibility that the Arun river is contributing to Mount Everest’s exceptional elevation presents an exciting insight into the mountain’s geological history.
