Name: Lascar
Address: World

Lascar is the most active volcano in the Central Andes of northern Chile. Standing at 5,592 meters (18,346 ft), it is a high-altitude sentinel located in the heart of the Atacama Desert, one of the most arid environments on the planet. Its name, possibly derived from the Quechua word for “tongue,” fits its behavior: it frequently licks the sky with flames and ash. Since the 19th century, Lascar has erupted more than 30 times, making it a priority target for scientific monitoring and a source of fascination for extreme mountaineers.

The High Desert Sentinel

Lascar sits on the edge of the Puna de Atacama, a high plateau that resembles the surface of Mars.

A Harsh Environment: The environment around Lascar is unforgiving. Strong westerly winds whip across the barren landscape, temperatures plummet well before freezing at night, and solar radiation is intense. There is almost no vegetation, save for clumps of resilient Ichu grass at the lower elevations.
Reaching the Summit: Climbing Lascar requires acclimatization. The trek starts at roughly 4,800 meters and ascends to the crater rim. Climbers are rewarded not with a view of a lush valley, but of a steaming, sulfuric pit and a 360-degree panorama of salt flats (Salar de Atacama) and other volcanoes, including the symmetrical Aguas Calientes.
The Fumaroles: Even when not erupting, Lascar breathes. Hundreds of fumaroles inside the active crater vent sulfur dioxide and hydrogen chloride gas. The hissing sound of escaping gas is the only noise in this silent, empty landscape.

The 1993 Cataclysm: A Continental Event

Lascar’s potential for violence was fully realized on April 19-20, 1993.

The Explosion: After a period of dome growth, the volcano unleashed a massive Vulcanian-to-Plinian eruption. The blast was so powerful that the eruption column collapsed, generating pyroclastic flows—avalanches of hot gas and rock—that raced 8.5 kilometers down the northwestern flank.
The Ash Cloud: The ash plume rose to an altitude of 25 kilometers (82,000 ft). The high-altitude winds carried this material eastwards across the continent. Ash fell in Santiago del Estero, Argentina, and fine particles were tracked as far as the Atlantic Ocean and southern Brazil.
Impact: While the immediate area is sparsely populated, the ash caused significant disruption to air traffic across South America. It poisoned water sources for the vicuña herds and impacted the subsistence farming of the small communities in the Andean foothills.

Cyclic Activity: The Lascar Rhythm

Volcanologists have identified a distinct cycle in Lascar’s behavior, often referred to as the “Lascar Cycle.”

Dome Growth: The cycle typically begins with the slow extrusion of a lava dome in the central crater. This dome acts like a plug in a pressure cooker, trapping gases beneath it.
Subsidence: As pressure builds, the crater floor may show signs of subsidence or deformation.
Explosion: Eventually, the pressure exceeds the strength of the rock. The dome is blasted apart in a violent explosive eruption (like the 1993 or 2015 events), clearing the vent.
Degassing: The cycle ends with a period of open degassing, where the volcano steams freely until a new dome begins to form, restarting the clock. Understanding this rhythm is key to predicting future large-scale events.

The Salt and the Fire: A Geological Synergy

To the west of Lascar lies the Salar de Atacama, the third-largest salt flat in the world and the planet’s largest source of lithium.

The Source: The lithium found in the brine of the Salar originates from the weathering of volcanic rocks in the Andes, including Lascar. Over millions of years, rain and snow have dissolved the mineral-rich rhyolitic ignimbrites erupted by Lascar and its neighbors, washing the lithium down into the closed basin of the Salar.
The View: From the summit of Lascar, the evaporation ponds of the lithium mines look like a geometric, colorful mosaic—a stark industrial contrast to the wild, natural forces of the volcano. This visual juxtaposition highlights the link between the fiery geological history of the region and the modern energy revolution powering electric vehicles.

Climbing Lascar: A Guide for the Brave

Ascending Lascar is one of the most accessible “high-altitude” summits in the Andes, but it is not to be underestimated.

The Approach: The journey begins in San Pedro de Atacama. A 4x4 vehicle is essential to navigate the dusty, washboard roads leading to Laguna Lejía, a stunning high-altitude lake filled with flamingos that often mirrors the smoking volcano. From there, the drive continues up to roughly 4,900 meters.
The Ascent: The hike itself is short in distance (about 3-5 km) but grueling due to the altitude. Climbers struggle for breath in the thin air, plodding up steep scree slopes. The cold is intense, often aggravated by biting winds that can freeze exposed skin in minutes.
The Summit Crater: The reward is looking into the active crater. It is a terrifying hole in the earth, roughly 800 meters wide and 300 meters deep. The bottom is often obscured by pulsating clouds of sulfur gas. The roar of the fumaroles is audible, a constant reminder that the mountain is merely sleeping, not dead.
Safety: Climbers must carry gas masks. A sudden shift in wind direction can envelop the rim in suffocating $\text{SO}_2$ gas. Furthermore, guides typically limit time at the crater rim to 15-20 minutes to minimize exposure to toxic fumes.

Monitoring from Space: The Satellite Sentinel

Because maintaining ground stations is so difficult, Lascar is a primary target for satellite volcanology.

InSAR Technology: Scientists use Interferometric Synthetic Aperture Radar (InSAR) to measure ground deformation from space. By comparing radar images taken at different times, they can detect if the volcano is inflating (swelling) or deflating. Inflation is often a sign that a new batch of magma is entering the shallow reservoir, warning of a potential eruption months in advance.
Thermal Anomaly Detection: Satellites like MODIS and Sentinel-2 continuously scan Lascar for heat. A subtle rise in the temperature of the crater floor can indicate that the lava dome is becoming more permeable or that fresh magma is rising near the surface. This remote thermal monitoring is the only way to keep a consistent eye on the volcano’s “fever” without risking human lives on the rim.

Environmental Extremes and Preservation

The unique climate of the Atacama Desert makes Lascar a geological library.

Preservation: Because there is so little rain to erode the landscape, volcanic deposits from thousands of years ago look as if they fell yesterday. Scientists can study the “fingerprints” of ancient pyroclastic flows with incredible precision.
Life on Mars: Astrobiologists study the environment around Lascar as a proxy for Mars. The combination of high UV radiation, extreme aridity, and oxidizing soils is similar to conditions on the Red Planet. Understanding how microbial life survives in the fumarolic vents of Lascar gives clues to where we might look for life elsewhere in the solar system.

High-Altitude Monitoring Challenges

Monitoring a volcano at 5,600 meters in a desert is a logistical feat.

The Network: The Southern Andes Volcano Observatory (OVDAS) maintains a network of telemetered seismometers. However, the extreme cold often drains batteries, and the high winds can destroy solar panels.
Infrasound: To supplement seismic data, researchers use infrasound arrays to “hear” the explosions. Since acoustic waves travel well through the atmosphere, these sensors can be placed further away in more accessible locations.
The Human Factor: The closest settlement is the small village of Talabre. The residents, mostly indigenous Likan Antai people, have a deep knowledge of the mountain. They are the first line of defense, often reporting changes in the color of the plume or the smell of sulfur before the instruments register a change.

The Likan Antai Legend

For the indigenous Likan Antai (Atacameño) people, the volcano is a respected elder.

The Tongue of Fire: The name “Lascar” is believed to refer to the “tongue” of fire or smoke that the volcano frequently sticks out. In local cosmology, the volcanoes are personified spirits that interact with one another.
The Punishment: Legends say that Lascar is a strict disciplinarian. When the people forget the old ways or show disrespect to the Pachamama (Mother Earth), Lascar smokes to warn them. The 1993 eruption is still spoken of by the elders of Talabre as a time when the mountain was truly angry, turning day into night to force introspection.
Offerings: To this day, hikers and locals often make small offerings of coca leaves or alcohol at the base of the volcano before attempting an ascent, asking for safe passage and clear weather.

Conclusion

Lascar is a raw, elemental force. It is a volcano stripped of the softness of vegetation, standing naked against the Andean sky. Its frequent explosions serve as a regular reminder that the earth beneath the Atacama is far from dead. For the scientist, it is a perfect laboratory; for the climber, a supreme challenge; and for the locals, a temperamental neighbor that demands constant respect and vigilance.