The quest to find the planet’s highest points often focuses on mountains, but volcanoes represent a specific and impressive category of geological giants. These towering landforms are dynamic structures built by the Earth’s internal forces, often growing to immense sizes. The search for the “tallest” among them reveals a complexity, as the answer depends entirely on the method of measurement used.
The World’s Highest Volcanic Peak
The volcano that holds the title for the highest elevation above sea level is Nevados Ojos del Salado. This massive peak is located in the Andes Mountains, straddling the border between Argentina and Chile. Ojos del Salado rises to an accepted elevation of 6,893 meters (22,615 feet) above sea level, making it the highest volcano on Earth.
This elevation secures its place as the second-highest mountain in the Western Hemisphere, surpassed only by nearby Aconcagua. The mountain is a stratovolcano, characterized by its steep, conical shape, built up over centuries by layers of hardened lava, ash, and pumice. Its height above the ocean surface is the standard measure by which it claims the record.
The name of the volcano, which translates to “Eyes of the Salty One,” references the large deposits of salt and saline lakes found in the region. This arid environment, close to the Atacama Desert, contributes to the mountain’s stark appearance. The peak is recognized as the highest point on the planet that is unequivocally a volcano.
How Volcanic Height is Measured
Determining the “tallest” volcano is complex, as different measurement criteria yield different results. The conventional method is measuring the height above sea level, which is the metric that gives Ojos del Salado its record. This approach uses the mean sea surface as a standardized zero point for comparison.
A second measure is the distance from the base of the structure to its summit, which reveals the true mass and scale of the edifice. By this metric, the Hawaiian volcano Mauna Kea is the champion. While its summit only reaches 4,205 meters (13,796 feet) above sea level, its base rests nearly 6,000 meters (19,685 feet) below the Pacific Ocean floor. The total height of Mauna Kea from base to summit is approximately 10,210 meters (33,500 feet), making it the tallest mountain structure in the world.
A third definition of height is the distance from the Earth’s center to the peak. Due to the planet’s rotation, the Earth is an oblate spheroid, bulging at the equator. This equatorial bulge means that mountains located near the equator are physically farther from the center of the Earth than peaks at higher latitudes. In this case, the stratovolcano Chimborazo in Ecuador takes the title. Its summit, though only 6,263 meters (20,548 feet) above sea level, is approximately 6,384.4 kilometers from the Earth’s center, surpassing even Mount Everest.
Profile of the Tallest Volcano
Ojos del Salado is classified as a massive stratovolcano, a composite cone built from layers of viscous lava and pyroclastic materials. It is situated within the Central Volcanic Zone of the Andean Volcanic Belt, a region formed by the subduction of the Nazca Plate beneath the South American Plate. This geological setting provides the conditions for its activity.
The volcano is considered the highest active volcano in the world, a designation based on persistent fumarolic activity observed near its summit. While no confirmed historical eruptions have been recorded, geological evidence suggests a large explosive eruption occurred between 1,000 and 1,500 years ago. Unconfirmed reports of minor gas and ash emissions were noted as recently as 1993, confirming its active status.
The environment surrounding Ojos del Salado is one of extreme aridity and temperature fluctuation, typical of the high Atacama region. Despite the harsh conditions, the volcano is home to the world’s highest permanent body of water, a small crater lake located at approximately 6,390 meters (20,964 feet). This lake attracts scientists studying extremophile organisms. The peak has two summits of nearly equal height, one in Chile and one in Argentina. Its challenging ascent makes it a significant objective for mountaineers, who must navigate scree, salt pans, and the severe lack of oxygen.