The Zombie Awakens: This Volcano Is Showing "First Signs" Of Unrest After 700,000 Years Of Quiet

After millions of years of peace, an idle volcano is showing its first signs of volcanic unrest. The summit of Taftan has become swollen and bloated, indicating that the pressure of magma and hot gas is increasing within its bowels. 

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The Taftan volcano is a 3,940-meter (12,927-foot) stratovolcano in southeastern Iran. It’s considered to be the only active member of the Makran continental volcanic arc, a trio of volcanoes on the Iran-Pakistan border created by one of Earth’s tectonic plates, the Arabian Plate, slowly sliding beneath another, the Eurasian Plate.

Though faintly active, it’s not known for its aggressive behavior. There were reports of it letting out smoke in 1902, plus unverified claims of a small lava flow in 1993, but it isn’t known to have erupted in human history. Scientists have previously estimated that the last major eruption occurred around 700,000 years ago, long before Homo sapiens had evolved.

However, perhaps this giant isn’t as gentle as once hoped. In a new study, volcanologists used satellite data to show the summit of the Taftan volcano swelled by around 9 centimeters (3.5 inches) between July 2023 and May 2024. The bloating is yet to die down.

Oddly, the bulging seems to be “spontaneous” and “triggerless,” the study authors note. Volcanic activity can be triggered by a variety of factors, from earthquakes shaking loose the plumbing system to changes in groundwater. Even a period of intense rainfall can shake things up. 

But in Taftan’s case, there’s no obvious culprit. This led the researchers to speculate that the bloating may be caused by magma being pushed upward due to a pocket of hot water and steam deep underground.

“We postulate that changes in gas permeability within the shallow part of the volcanic edifice and/or undetected deep magmatic intrusions could have led to the observed pressure buildup in a volume of the hydrothermal system around 460–630 meters [1,509-2,067 feet] beneath the surface,” the study authors write. 

This doesn’t suggest that an explosive eruption is due any day now. It does, however, show that Taftan is not the sleepy “zombie” that many assumed it to be. If that’s the case, volcanologists and authorities will need to stay on high alert, boosting monitoring systems and gearing up for the day Taftan truly wakes.

“Our findings reveal that Taftan is more active than previously recognized,” the study authors conclude.

“This highlights the urgent need for a revision of the current volcano risk of the Makran subduction volcanic arc, that is, establishing volcano monitoring networks, creating and/or updating geological hazard maps and other measures aiming to reduce volcanic risks,” they added. 

The study is published in the journal Geophysical Research Letters.