Mount Everest, our planet’s highest peak at 29,032 feet, continues to defy expectations by growing taller each year.
While most assume tectonic forces push the peak skyward, a study in Nature Geoscience shows an unexpected player in this vertical dance: two ancient rivers that merged 89,000 years ago.
But what could this discovery tell us about the future of Earth’s highest peak?
The River Connection
The story begins approximately 89,000 years ago when the Kosi River merged with the Arun River, creating a powerful combined waterway system about 50 miles from Everest. (ref) This merger initiated an intense erosion process, removing massive amounts of rock and soil from the Himalayan foothills.
Rather than diminishing the mountain’s height, this erosion triggered a remarkable phenomenon known as isostatic rebound.
The process works similarly to a boat rising in water when cargo is removed. As the merged rivers carried away billions of tons of sediment, the reduced weight on the Earth’s crust caused the land to float higher on the semi-liquid mantle beneath.
This geological response has contributed an additional 49.2 to 164 feet to Everest’s height over the past 89,000 years.
Measuring the Growth
The mountain’s growth rate has surprised researchers, with GPS measurements confirming an upward movement that outpaces surface erosion.
- Current growth rate: 0.08 inches per year
- Isostatic rebound contribution: 0.0063-0.021 inches annually
- Total height gained: 50-150 feet over 89,000 years
This continuous uplift affects not only Everest but also its neighboring peaks, including Lhotse and Makalu, though Everest maintains its commanding lead of nearly 800 feet above its closest rivals.
The Geological Ballet
The Earth’s crust beneath the Himalayas performs a delicate balance, floating like a raft atop the denser liquid rock of the mantle. This mountain range extends an impressive 155 miles below the surface, creating a massive root system that responds to changes in surface weight.
The erosional activity of the merged Kosi-Arun river system has effectively lightened the crustal load, allowing the mountains to rise higher in response.
This discovery challenges the traditional understanding of mountain formation, focusing solely on tectonic activity.
The research demonstrates how river dynamics can significantly influence the height of Earth’s greatest peaks, showcasing the interconnected nature of geological processes.
Future Implications
The ongoing uplift suggests that Everest hasn’t finished growing yet. As erosion continues, the rate of isostatic rebound may potentially increase.
This process represents a fascinating example of how Earth’s systems work in unexpected ways. The removal of material paradoxically leads to increased elevation.
- Continuous monitoring through GPS stations
- Potential for accelerated growth rates
- Impact on surrounding peak elevations
Impact on Glaciers & Ice Cover
The Himalayan glaciers around Mount Everest are experiencing unprecedented changes due to climate change. The South Col Glacier, the world’s highest at approximately 25,938 ft, has lost 180 feet thickness of ice formation in just 25 years. (ref)
The average temperature on Everest has risen at a rate of 0.36–0.54°F per decade, with higher elevations experiencing more rapid warming.
The Khumbu Glacier (ref) near Everest Base Camp is now “very close to the melting point,” making it susceptible to rapid melting with even small increases in atmospheric temperature.
Climbing Conditions & Safety Risks
Climate change is making climbing Mount Everest increasingly challenging and unpredictable. The warming temperatures are affecting both the mountain’s topography and traditional weather patterns that climbers rely on for planning expeditions.
The Khumbu Icefall, a crucial route to Camp 1, has become less reliable and more dangerous due to increased instability. (ref)
Melting permafrost is exacerbating rockfall risks, especially in high mountain areas where formations are held together by frozen ground.
The traditional “magical” climbing window in May is becoming more erratic, with changing wind patterns and weather conditions making it harder for climbers to plan safe expeditions.
Source:
Read Next
When measuring mountains, appearances can be deceiving. While Mount Everest soars to an impressive 29,032 feet above sea level, America’s own Denali holds a remarkable secret.
Read Next:
Nancy Maffia
Nancy received a bachelor’s in biology from Elmira College and a master’s degree in horticulture and communications from the University of Kentucky. Worked in plant taxonomy at the University of Florida and the L. H. Bailey Hortorium at Cornell University, and wrote and edited gardening books at Rodale Press in Emmaus, PA. Her interests are plant identification, gardening, hiking, and reading.