
The Earth's tallest peak continues to grow taller over time.
It might seem that Mount Everest, nature’s colossal skyscraper, would shrink gradually each year due to erosion or similar forces. However, it remains on the rise, and science now offers a clearer explanation for this growth.
A study published in the journal Nature Geoscience, conducted by a team of researchers from London and Beijing, proposes that erosion plays a role—but it actually benefits the mountain. The erosion at the point where the Arun and Kosi rivers converge, located 47 miles from Everest, slowly wears away the rock. Over tens of thousands of years, the reduction in the weight of rock pressing down on the Earth's surface has allowed it to rise through a process called isostatic rebound. As the crust lightens, it ‘floats’ above the mantle, which lifts Everest higher into the sky.
According to Adam Smith, a co-author of the paper, the Himalayas could be metaphorically described as resting on 'a bouncy castle,' as he told The New York Times.
Through computer modeling, researchers estimate that Everest grows by approximately 2 millimeters each year. Over the course of 89,000 years since the merging of the Arun and Kosi rivers, this growth could account for an additional 50 to 165 feet, though Everest has likely been gradually increasing in height all along. This process may outpace the erosion that would otherwise reduce its size.
Dr. Jin-Gen Dai, a co-author of the study, remarked in a statement, 'An intriguing river system exists in the Everest region. The Arun river flows east at high altitude with a flat valley, before suddenly shifting south as the Kosi river, descending in elevation and becoming steeper. This unusual topography, indicative of instability, is likely connected to Everest's extraordinary height.'
The phenomenon is also observed in the nearby Lhotse and Makalu peaks, which rank among the tallest in the world.
Currently, Everest stands at 29,032 feet above sea level, a measurement that was only finalized after years of dispute. Nepal had initially reported it as 29,029 feet, while China considered it to be 29,015 feet after subtracting the snow layer.
Although Everest is widely considered the tallest mountain in the world, this claim can be debated when examined more closely. For instance, Mauna Kea in Hawaii reaches a height of 30,610 feet, although most of it lies beneath the ocean’s surface.
While many experts have praised the new study, they also caution that accurately measuring the total impact of river erosion can be challenging. Additionally, it’s likely not the only factor contributing to Everest’s ongoing growth.
It’s possible that, eventually, the isostatic rebound may stop, causing Everest to begin sinking. However, for the time being, this natural wonder doesn't seem ready to stop expanding.
