A long-dormant volcano in southeastern Iran has recently awakened from its slumber, and scientists are paying close attention. This volcano, known as Taftan, has shown signs of activity after an astonishing 700,000 years of silence. But here's where it gets controversial: this volcano, despite its prolonged inactivity, is not considered extinct. And this is the part most people miss - volcanoes can remain dormant for incredibly long periods, only to spring back to life unexpectedly.
A recent study has revealed that Taftan has risen by approximately 3.5 inches in just 10 months. This might seem like a minor shift, but it carries significant implications. Using satellite data, researchers have detected a build-up of pressure near the summit, indicating that something is stirring beneath the surface.
The study, led by Pablo J. González from the Spanish National Research Council, utilized a radar method called InSAR to track the ground motion from space. This advanced technology, combined with Sentinel-1 satellites, allowed scientists to monitor the remote Taftan volcano, which lacks on-site instruments due to its isolated location.
The uplift, which occurred between July 2023 and May 2024, was centered near the summit and has not subsided, suggesting that the pressure remains. The team modeled the source of this pressure to be relatively shallow, around 1,600 to 2,070 feet below the surface. This depth indicates the presence of gases moving and collecting within a hydrothermal system beneath the volcano.
The researchers ruled out heavy rain and nearby earthquakes as triggers, as the signal rose independently and slowed without external influence. This pattern suggests internal processes at play within the volcano's structure. Deeper down, the magma reservoir, a large body of molten rock, lies more than 2 miles underground. The current activity is likely driven by gases above the magma, rather than fresh magma reaching the surface.
The pattern of the uplift resembles a slow squeeze, with the ground rising and then stabilizing as new cracks form, allowing some gas to escape. This activity highlights the importance of not relying solely on labels like "extinct" when it comes to volcanoes. Taftan, despite its lack of recorded eruptions in human history, is a stratovolcano built from layers of lava and ash, and its summit fumaroles, emitting gas, indicate an active system.
The potential risks associated with Taftan are not lava flows but phreatic blasts, steam-driven explosions that can occur when hot fluids flash to vapor near the surface. These explosions can release gases that irritate eyes, lungs, and crops downwind. The nearby city of Khash, situated about 31 miles away, is close enough to detect sulfur odors when the wind aligns.
González emphasizes that this study is not intended to cause panic but to serve as a wake-up call to the authorities in the region. The message is clear: prepare now, while the volcano is giving subtle signals, rather than waiting for a more dramatic event.
Scientists plan to measure gases at the vents and on the slopes to monitor sulfur dioxide, carbon dioxide, and water vapor levels. They also advocate for a basic network of seismometers and GPS units to capture seismic activity and ground deformation. Satellites will continue to provide crucial updates, and field crews can respond quickly to any detected changes.
Taftan's location in a subduction zone, where one tectonic plate slides under another, creates the conditions for magma formation and gas-rich fluids. The volcano's two main peaks and long-lived gas vents indicate that heat continues to rise from below. While many volcanoes show similar slow changes without erupting, others can ramp up quickly after a quiet phase.
The key takeaway is that consistent monitoring saves lives. It transforms potential surprises into known problems with established response plans.
Radar satellites, like Sentinel-1, play a vital role in this process, as they can see through clouds and operate day and night. This technology is particularly valuable in dry, high-altitude regions with harsh weather conditions. As more satellites are launched, revisit times will decrease, providing scientists with faster updates.
The combination of space-based monitoring and on-site instruments offers the best approach. Satellites provide a broad overview, while instruments on the mountain offer detailed insights.
If the ground at Taftan starts to sink, it could indicate that pressure is easing, and gas has found new exit paths. Continued or accelerated uplift suggests that pressure is still building, increasing the likelihood of steam events. Sharp changes in gas measurements or tiny quakes under the summit would also be cause for concern.
For nearby communities, simple preparedness measures are essential. Understanding wind patterns, keeping masks handy for sulfur odors, and following official guidance can make a significant difference.
The study, published in Geophysical Research Letters, highlights the importance of ongoing research and monitoring to ensure the safety of those living in the shadow of active volcanoes.
