Nevado Ojos del Salado: The World's Highest Volcano

Nevado Ojos del Salado is the highest volcano on Earth, rising to 6,893 meters (22,615 feet) on the border between Argentina and Chile in the Andes. It is also the second-highest mountain in the Western Hemisphere (after Aconcagua at 6,961 m) and the highest peak in Chile. Despite its immense elevation and volcanic origin, Ojos del Salado sits in one of the driest places on Earth — the Atacama Desert — giving it a stark, otherworldly appearance.

Introduction

The volcano's activity status is debated among geologists. While there are no recorded historical eruptions, the presence of active fumaroles near the summit, young-looking lava flows, and a small permanent crater lake at approximately 6,390 m — believed to be the highest lake in the world — suggest that Ojos del Salado may be dormant rather than extinct. This combination of extreme altitude, volcanic uncertainty, and remote desert setting makes it one of the most fascinating peaks on the planet.

Geology & Dimensions

• Elevation: 6,893 m (22,615 ft)
• Type: Stratovolcano
• Location: Atacama Region, Chile / Catamarca Province, Argentina
• Tectonic Setting: Nazca Plate subducting beneath South American Plate
• Last Known Activity: ~750 AD (disputed) or ~1,000-1,500 years ago

Ojos del Salado is part of the Central Volcanic Zone of the Andes, formed by the subduction of the Nazca Plate beneath the South American Plate. The volcano has been built over hundreds of thousands of years through the accumulation of andesitic and dacitic lava flows, pyroclastic deposits, and volcanic sediments. Its extreme height is partly due to the thickened continental crust in this region of the Andes.

The most recent eruptive activity is estimated at approximately 1,000-1,500 years ago, based on the dating of young lava flows on the upper flanks. A report from 1993 described sulfurous gas emissions and an ash plume, though this was never confirmed. Active fumaroles near the summit release sulfur gases, and the presence of sulfur deposits and a small crater lake suggest ongoing hydrothermal activity connected to a cooling magma body at depth.

The Highest Lake in the World

• Elevation: ~6,390 m
• Diameter: ~100 m
• Depth: ~10 m (estimated)
• Temperature: Often partially frozen
• Status: Likely the world's highest lake

At approximately 6,390 meters on Ojos del Salado's eastern flank sits a small crater lake that is believed to be the highest permanent body of water in the world. The lake is roughly 100 meters in diameter and approximately 10 meters deep, fed by snowmelt and possibly hydrothermal fluids. It is frequently partially frozen and its vivid blue color contrasts dramatically with the barren volcanic terrain.

The existence of a permanent lake at this extreme altitude is remarkable. The Atacama Desert receives virtually no precipitation at these elevations, and intense solar radiation and low atmospheric pressure promote rapid evaporation. The lake's persistence suggests a subsurface water source, possibly related to volcanic hydrothermal activity. Its exact status as the "world's highest lake" is occasionally challenged by smaller water bodies found at similar altitudes on other Andean peaks.

Mountaineering

• First Ascent: February 26, 1937 — Jan Szczepański and Justyn Wojsznis (Poland)
• Normal Route: Chilean approach via Laguna Verde
• Altitude Record: Highest point reached by a vehicle: 6,688 m (Gonzalo Bravo, 2007)
• Technical Difficulty: Non-technical to ~6,500 m; Class 3 scrambling near summit

Ojos del Salado is considered the highest non-technical peak in the world — most of the ascent involves hiking and scrambling over volcanic scree, with only the final 50-meter summit pyramid requiring Class 3 rock scrambling. However, the extreme altitude makes it a serious undertaking: altitude sickness, extreme cold (temperatures can drop below -30°C), and fierce winds are the primary challenges.

The standard approach is from the Chilean side via Laguna Verde, with a series of mountain refuges (including the Atacama and Tejos huts) providing shelter during the multi-day ascent. The Argentine approach from the east is longer but offers the advantage of a higher base camp. In 2007, Chilean Gonzalo Bravo drove a modified Suzuki Samurai to 6,688 meters on the slopes — the highest altitude ever reached by a wheeled vehicle.

Environment & Extremes

• Desert Setting: Eastern Atacama Desert — one of the driest places on Earth
• Precipitation: Effectively zero in many years
• Temperature Range: -30°C to +10°C at summit region
• UV Radiation: Among the highest recorded on Earth

Ojos del Salado's setting in the Atacama Desert makes it one of the most extreme environments on the planet. Annual precipitation at its base is often measured in single-digit millimeters, and some years see no measurable rainfall at all. The air at 6,893 meters contains only about 40% of the oxygen available at sea level, and UV radiation levels are among the highest recorded anywhere on Earth.

Despite this extreme aridity, life persists. Hardy lichens have been found at elevations above 6,000 meters, and vicuñas — wild relatives of llamas — graze on sparse vegetation at the volcano's base. The area has been studied by NASA as an analog for Martian conditions, and the extreme dryness has preserved geological features and volcanic deposits in remarkable detail.

Key Facts

• Ojos del Salado at 6,893 m is the world's highest volcano and Chile's highest peak.
• A crater lake at ~6,390 m is believed to be the highest permanent lake in the world.
• The volcano has not erupted in recorded history but has active fumaroles near the summit.
• The highest altitude ever reached by a wheeled vehicle (6,688 m) was on Ojos del Salado's slopes.
• The volcano sits in the Atacama Desert, one of the driest environments on Earth.

Fun Facts

• Despite being the world's highest volcano, Ojos del Salado is often overlooked because nearby Aconcagua (6,961 m) steals the "highest in the Americas" title.
• The name "Ojos del Salado" means "Eyes of the Salty One," referring to salt deposits on its glaciers or the lagoons at its base.
• NASA has used the area around Ojos del Salado as a testing ground for Mars rovers due to its Mars-like terrain.
• A volcanic driving record was set here in 2007 — reaching 6,688 m, higher than the summit of Kilimanjaro.

Final Thoughts

Nevado Ojos del Salado is a volcano of superlatives: the highest on Earth, home to the world's highest lake, site of the highest vehicular altitude record, and set in one of the driest deserts on the planet. Its disputed activity status adds an element of geological mystery to an already extraordinary peak. For mountaineers and volcanologists alike, it represents one of the most extreme and fascinating places on Earth.