After 700,000 years of silence, this Iranian volcano is showing signs of an unexpected awakening

A Geological Awakening After Millennia of Silence

After lying dormant for nearly 700,000 years, a volcano in southeastern Iran is showing signs of activity that have intrigued the scientific community. A ground elevation of approximately 3.5 inches, or 9 centimeters, was recorded over a ten-month period. While this figure may seem modest at first glance, it is of major importance to geologists, as it indicates rapidly evolving underground dynamics.

The volcano in question is Taftan. Although no eruptions have been recorded in human history, this new signal clearly indicates that the system is becoming active and requires increased monitoring. A recent study, based on satellite data, identified this change and supports the hypothesis that pressure is building near the summit.

Observation of this uplift, which lasted just over ten months and was concentrated near the summit, reveals that the ground did not subsequently subside. This persistence suggests that the internal pressure has not yet dissipated. The Taftan volcano, isolated and lacking ground-based measuring instruments such as continuous GPS receivers, now relies on space technology for monitoring. This is the most effective way to keep an eye on this rarely visited mountain, whose slopes are still home to many towns.

Space Technology for Monitoring

To analyze this phenomenon, scientists tracked ground movements using InSAR, a radar method capable of measuring ground deformation from space. They used the Sentinel-1 satellites, which operate both day and night and can see through clouds. Pablo J. González, of the Spanish National Research Council at the Institute of Natural Products and Agrobiology (IPNA), is the lead author guiding this research.

The team modeled a pressure source located only between 1,600 and 2,070 feet (490 to 630 meters) below the surface. This shallow depth suggests the presence of gases moving and accumulating within a hydrothermal system, where hot water and gases circulate beneath the volcano. The researchers tested the usual causes and ruled out heavy rainfall and nearby earthquakes as triggers. The signal increased and then slowed down without any external influence, consistent with internal processes occurring at the heart of the volcano.

Deeper down, more than 2 miles (3.2 kilometers) underground, lies the magma chamber—a large mass of molten rock. The current pressure is therefore likely coming from gases above this chamber, rather than from fresh magma reaching the surface. The pattern resembles a slow compression: the ground first rose, then stabilized as new fissures opened and some gases found escape routes.

Beyond Common Misconceptions: The Invisible Activity

Taftan Volcano is a stratovolcano rising to 12,927 feet (3,940 meters), a rugged mountain built up by successive layers of lava and ash. It releases gases through summit fumaroles—volcanic vents that prove the system is still active. Records of eruptions over the past 10,000 years are scarce, which complicates analysis. However, the absence of written records does not mean the system is geologically dead.

Labels such as “extinct volcano” can be misleading. Volcanoes can remain inactive for long periods and then change their behavior within a few months. That is why scientists do not rely solely on ash plumes as early warning signs. They also pay attention to gases, heat, and ground movements. The newly observed deformation is a factual measurement, far more significant than a simple classification label.

This magma-free uplift is likely driven by the accumulation of gas in impermeable rocks and fractures. As gas pressure increases, the rock rises slightly, and the summit area reacts first. Another possibility is a small melting event that released volatiles—gases escaping from magma—into the shallower plumbing system. These gases percolate upward and inject pressure into the pores. Both of these hypotheses are consistent with the shallow source and the observed timing. The data also show that, once the gas found pathways to escape, the rate of uplift slowed.

Real Risks and a Call for Vigilance

None of this necessarily implies an imminent eruption, but the situation warrants attention because the pressure must find an outlet. The main short-term dangers are not lava flows, but phreatic explosions. These are steam-driven explosions that can occur when hot fluids instantly turn to steam near the surface.

Gas plumes can irritate the eyes and lungs and affect crops downwind for a short period. The town of Khash is located about 31 miles (50 kilometers) away—close enough to smell sulfur when the wind is blowing in the right direction. Pablo J. González explains the situation pragmatically: “This is bound to be released one way or another in the future, either violently or more calmly. This study is not intended to cause panic among the public. It is a wake-up call for regional authorities in Iran to allocate resources to investigate this.”

These warnings are clear, but they are not doomsday predictions. The message is to prepare now, while the mountain whispers, rather than wait until it screams. The full study was published in the journal Geophysical Research Letters.

Monitoring to Better Anticipate the Future

Looking ahead, the scientific teams hope to measure gases directly at the vents and on the slopes. Continuous readings of sulfur dioxide, carbon dioxide, and water vapor levels can indicate whether pressure is increasing or decreasing. They are also calling for the establishment of a baseline network consisting of seismometers and GPS units to capture tremors and slow ground deformations. Even a modest setup would help refine the timing and reduce blind spots.

Satellites will continue their monitoring. InSAR radar can detect small changes that field teams can verify within a few days. Sentinel-1 carries a C-band radar that passes over the same area frequently enough to create a true “movie” of the movement. These repeated observations are key when the change is only a few inches. Space and ground-based instruments work best together: satellites scan the big picture, and instruments on the mountain add the details.

If the ground begins to subside, it will mean that pressure is decreasing and that the gas has found new outlets. If uplift continues or accelerates, pressure continues to build, and the risk of steam events increases. Sudden changes in the tiny earthquakes beneath the summit would also be cause for concern. For nearby communities, simple precautions can help: be aware of wind patterns, keep masks on hand for sulfur odors, and follow official guidelines. Constant, routine monitoring saves lives by turning surprises into known problems with known solutions.

Source: earth.com

After 700,000 years of silence, this Iranian volcano is showing signs of an unexpected awakening