Mount Everest's Height Growth Linked to 89,000-Year-Old River Merger, Study Reveals

Measuring an impressive 29,032 feet above sea level, Mount Everest stands tall compared to its Himalayan neighbors by hundreds of feet. However, recent scientific findings reveal that the world's tallest peak is continuously growing, partly due to the merger of two nearby river systems tens of thousands of years ago. This remarkable discovery was published in a study in the journal Nature Geoscience.

Geomorphic Changes, Forces at Play

Dai Jingen, a geoscientist at China University of Geosciences in Beijing and a co-author of the study, shared his insight with NBC News, stating, "Even a feature as seemingly permanent as Mount Everest is subject to ongoing changes driven by various geological forces." The peak of Everest has been consistently gaining height, along with the rest of the Himalayas, since its formation approximately 45 million years ago, resulting from the collision of the tectonic plates beneath the Indian subcontinent and Eurasia.

River Systems and Their Impact

However, this explanation did not entirely clarify the surge in Everest's height. Researchers have now established that when the Kosi river overtook the Arun river around 89,000 years ago, it gave rise to a potent combined river that eroded substantial amounts of rock and soil from the Himalayan base nearly 50 miles away from Everest. This intense erosion triggered a geological process known as isostatic rebound, alleviating the area's weight and facilitating the rise of land masses on the Earth's crust, the outermost layer that floats atop a hot, semi-liquid rock mantle.

Elevation Insights and Surprising Dimensions

Dai explained that as the river eroded more rocks, the Earth's crust rebounded, akin to a boat rising when weight is removed. This intricate connection between erosion and crust movement has significantly contributed to the elevation of Everest, with scientists estimating that the rebound is causing its growth at a rate of 0.16 to 0.53 millimeters per year, accounting for up to half of its annual uplift rate. Notably, Everest's annual growth has been measured at up to 2 millimeters in recent years.

Implications for Himalayan Formation Models

These revelations prompt a deeper understanding of Everest's extraordinary height, raising its stature to nearly 800 feet taller than its neighbors. Dai emphasized that the role of river capture and erosion-related isostatic rebound in Everest's elevation adds a surprising dimension to the study of mountain formation, typically attributed to tectonic activity. He underscored the findings' potential to reshape current models of Himalayan formation and evolution, urging a re-examination of established notions.

Interconnectedness of Earth Systems

Furthermore, Dai emphasized the significance of recognizing the Earth as an interconnected system, where changes in one area can yield remarkable and significant effects elsewhere. This perspective calls for a holistic view of geological phenomena and their far-reaching impacts, underscoring the complexity of Earth's dynamic systems. The ongoing growth of Mount Everest provides profound insights into the intricate interplay of natural processes that shape our planet over millions of years.