A volcano in southeastern Iran that has remained dormant for nearly 700,000 years is showing subtle but significant signs of renewed activity, according to a new scientific study that has raised concerns among volcanologists.
Researchers have detected a gradual uplift of around nine centimetres near the summit of Mount Taftan over a ten-month period, a movement identified using satellite radar observations. While the rise may appear minor, scientists say it indicates increasing pressure beneath the volcano and warrants close monitoring.
Mount Taftan has no recorded eruptions in human history and is often considered inactive. However, the new deformation signal suggests that internal volcanic processes are underway. The study, published in Geophysical Research Letters used data from the European Space Agency’s Sentinel-1 satellites, which rely on Interferometric Synthetic Aperture Radar, or InSAR, to measure minute ground movements from space.
The uplift was concentrated near the summit and, importantly, has not subsided. According to the researchers, this persistence indicates that the pressure causing the ground to rise has not yet been released. The volcano’s remote location and lack of on-ground monitoring equipment mean satellite observations are currently the most reliable way to assess its behaviour.
Scientists involved in the study believe the pressure source lies relatively close to the surface, between 490 and 630 metres underground. This depth suggests the activity is likely linked to gas accumulation within Taftan’s hydrothermal system rather than molten magma rising toward the surface. Deeper magma reservoirs remain more than three kilometres below ground.
After analysing possible external triggers, researchers ruled out heavy rainfall and nearby earthquakes. Instead, they concluded that internal volcanic processes, such as gas buildup within fractures and porous rock, are the most likely cause of the uplift.
Mount Taftan is a steep stratovolcano standing nearly 4,000 metres tall and is known for its active fumaroles, vents that continuously release volcanic gases. These emissions already indicate that heat and gases are still moving beneath the volcano, despite its long period of dormancy.
Volcanologists caution against relying on labels such as “extinct” or “inactive.” Long quiet periods do not necessarily mean a volcano is dead. Many volcanoes around the world have remained silent for thousands of years before showing renewed activity over relatively short timescales.
The immediate risk posed by Taftan is not expected to be lava flows or large eruptions. Instead, scientists warn of possible phreatic explosions, sudden steam-driven blasts that occur when hot fluids rapidly turn into vapour near the surface. Such events can release ash and toxic gases without warning and pose risks to nearby communities.
The city of Khash, located about 50 kilometres away, is close enough to occasionally experience sulphur smells carried by the wind. Short-term gas releases could irritate eyes, lungs and crops, depending on wind direction and intensity.
Researchers emphasise that the findings are not meant to create panic but to encourage preparedness. Monitoring gas emissions, installing basic seismic and GPS instruments, and developing hazard maps could significantly improve early warning capabilities.
Satellite monitoring will continue to play a critical role. Radar-based systems like Sentinel-1 can detect ground changes of just a few centimetres and provide frequent updates, especially in regions where harsh terrain limits fieldwork.
Scientists say the future behaviour of Mount Taftan will depend on how the built-up pressure is released. A gradual release could reduce risk, while continued uplift or increased gas emissions may signal rising danger.
For now, the volcano is not erupting. But as researchers stress, it is no longer silent. The slow movement detected beneath Mount Taftan is a reminder that even ancient volcanoes can awaken and that early attention is the key to reducing future risk.