What Is the Tallest Mountain in the World?
Explore how Earth's tallest mountain is measured, the role of geological forces in its formation, and why different methods yield varying height rankings.
Mountains have long captured human fascination, representing both natural wonders and extreme challenges. Determining the tallest among them depends on measurement criteria.
Determining Earth’s Highest Peaks
Measuring a mountain’s height is more complex than it seems. The most widely accepted method uses elevation above sea level, placing Mount Everest at the top with an official height of 8,848.86 meters (29,031.7 feet), as confirmed by a 2020 survey by China and Nepal. This measurement, from summit to mean sea level, serves as the standard in geography and science. However, alternative methods challenge Everest’s status.
One approach measures height from base to summit. By this metric, Mauna Kea in Hawaii surpasses Everest. Its peak reaches only 4,207 meters (13,803 feet) above sea level, but its base lies on the Pacific seafloor. When measured from its foundation, Mauna Kea extends approximately 10,211 meters (33,500 feet), making it the tallest in total height.
Another perspective considers a mountain’s height relative to Earth’s center. Due to the planet’s equatorial bulge, locations near the equator sit farther from the core than those at higher latitudes. Chimborazo, a stratovolcano in Ecuador, benefits from this effect. Though its elevation is 6,263 meters (20,548 feet) above sea level, its summit is the farthest point from Earth’s center, exceeding Everest by over 2,000 meters.
The Himalayan Formation
The Himalayas, home to Earth’s highest peaks, formed from the collision of the Indian and Eurasian tectonic plates, a process still underway. Around 50 million years ago, the Indian plate, moving northward at about 15 centimeters per year, collided with the Eurasian plate. Unlike typical subduction events, where one plate slides beneath another, both plates’ low density prevented significant subduction. Instead, the immense force caused the crust to fold and thrust upward, creating the Himalayas.
Massive thrust faults, such as the Main Central Thrust and the Main Boundary Thrust, accommodated the stress from ongoing plate movement, stacking rock layers and increasing elevation. Erosion from rivers and glaciers shaped the rugged terrain, yet the Himalayas continue to rise at about 5 millimeters per year.
The range’s composition reflects its geological history, consisting of ancient marine sediments, metamorphic rocks, and granitic intrusions. Fossilized marine organisms found in high-altitude limestone provide evidence that these mountains were once part of an ancient seabed before being uplifted. This geological record helps scientists reconstruct the region’s tectonic evolution.
Comparing Sea-Level and Submarine Measurements
A mountain’s height varies depending on measurement criteria. Elevation above sea level remains the most accepted standard, providing a consistent reference for global comparisons. However, this method does not account for mountains extending beneath the ocean.
Submarine measurements consider a mountain’s full extent, including submerged portions. Mauna Kea exemplifies this approach. Its summit reaches only 4,207 meters above sea level, but its base lies deep on the Pacific seafloor. When measured from its foundation, Mauna Kea rises about 10,211 meters, exceeding Everest’s elevation. This highlights the limitations of relying solely on sea-level measurements.
Geophysical factors further complicate comparisons. Sea level fluctuates due to gravitational variations, ocean currents, and thermal expansion. Additionally, Earth’s equatorial bulge means regions near the equator sit farther from the planet’s center than areas near the poles. This gives Chimborazo an advantage when measured from Earth’s core rather than sea level. These disparities demonstrate that the definition of the tallest mountain depends on the chosen metric.