New Heights

Adventurers seeking to scale Mount Everest, the world’s tallest mountain, will find the task more challenging in the future.

The mountain, currently standing 29,032 feet high, has been growing, according to a new study.

Recent analysis showed that the iconic peak has gotten 50 to 164 feet bigger over the past 89,000 years – and it’s still rising.

The unexpected culprit? A nearby river that has been eroding the landscape and triggering the mountain’s uplift.

Researchers from University College London (UCL) and China’s University of Geosciences discovered that the Arun River, located about 46 miles east of Everest, has been steadily carving out a deep gorge.

As the river erodes the land, it reduces the weight pressing down on the Earth’s crust, allowing the ground beneath the mountain to rebound upward in a process called “isostatic rebound.”

As a result, the titanic peak is growing by about 0.08 inches a year, a rate higher than previously expected. This extra height boost helps explain why Everest towers roughly 820 feet above its neighboring Himalayan peaks, such as Lhotse and Makalu – even as they grow, too.

“It’s a new additional component of uplift for Mount Everest,” co-author Matthew Fox told the Washington Post. “The biggest impact is probably on the climbers that have to climb another 65 feet or so to the top.”

However, not everyone is sold on the idea. Geologist Mike Searle of Oxford University, who was not involved in the study, remains skeptical, noting that river incision may have limited influence on mountain growth.

“The main process causing the height of Everest and Makalu is tectonics: The thrusting of plates causes topography,” he told the newspaper.

Still, the study offers new insights into how the world’s tallest mountain is shaped by forces above and below the Earth’s surface, according to lead author Xu Han.

“The changing height of Mount Everest really highlights the dynamic nature of the Earth’s surface,” he explained in a statement. “The interaction between the erosion of the Arun River and the upward pressure of the Earth’s mantle gives Mount Everest a boost, pushing it up higher than it would otherwise be.”