Isostatic rebound: Mount Everest is growing faster

Mount Everest, towering at 8.85 kilometers above sea level, is still increasing in height, according to recent findings.

Hyderabad: Mount Everest, towering at 8.85 kilometers above sea level, is still increasing in height, according to recent findings. The Himalayas, including Everest, began forming about 50 million years ago due to the collision between the Indian subcontinent and the Eurasian plate. While this historical tectonic activity has contributed to the region’s steady uplift, researchers have discovered that Everest’s rise has been more significant than previously expected.

A major factor behind this unexpected growth is the interaction between two nearby river systems, the Kosi and Arun Rivers. These rivers merged roughly 89,000 years ago, and their unification has influenced the mountain’s elevation. This change has contributed to an uplift of about 49 to 164 feet, with the rate of elevation increasing at around 0.01 to 0.02 inches annually.

---

This phenomenon, known as isostatic rebound, explains how Earth’s crust reacts to changes in surface weight. When heavy materials, such as ice or rock, are removed, the land beneath gradually rises in response, much like a boat lifting when cargo is offloaded. In this case, the extensive erosion caused by the merging of the rivers reduced the weight of the region surrounding Everest, enabling the crust to rise.

Researchers used numerical models to simulate how these river systems evolved and found that isostatic rebound accounts for about 10% of Everest’s annual uplift rate. GPS measurements have confirmed this ongoing increase in elevation, which surpasses the effects of surface erosion from wind, rain, and river flow.

This process is also impacting nearby peaks like Lhotse, the fourth-highest mountain, which experiences nearly the same rate of uplift as Everest. Makalu, the fifth-highest mountain and closer to the Arun River, is rising at a slightly faster rate. The study suggests that as erosion continues, Everest’s growth due to isostatic rebound could further accelerate.

In Scandinavia, the land continues to rise due to isostatic rebound following the melting of Ice Age glaciers. This process, still ongoing, is reshaping coastlines and landscapes, with parts of the region rising up to 1 centimeter annually