Study debunks claim Iran earthquake triggered by nuclear test

By Stephen Beech

A major earthquake in Iran was not triggered by a nuclear test as feared, according to new research.

The study debunks claims that the 4.5 magnitude quake was a covert nuclear weapons test by the Iranian regime - as widely claimed on social media and by some mainstream news outlets in October 2024, a period of heightened tensions in the Middle East.

The American-led research, published in the journal Seismica, warns about the potential consequences of mishandling and misinterpreting scientific information, particularly during periods of international conflict.

Study leader Dr. Benjamin Fernando, a seismologist at Johns Hopkins University in Baltimore, said: “There was a concerted misinformation and disinformation campaign around this event that promoted the idea this was a nuclear test, which is not something you often see happen with an earthquake.

“This shows how geophysical data played an important role in a geopolitical crisis.”

The earthquake occurred on Oct. 5, 2024, around 30 miles southwest of Semnan, a city in northern Iran that is prone to earthquakes as it sits within a seismically active region.

Dr. Fernando’s team analyzed seismic signals from the event, identifying natural seismic activity caused by the earthquake.

Using publicly available data from seismic monitoring stations, the research team concluded that the quake originated along a gently sloping fault where Earth’s crust was being deformed by the collision between Arabia and Eurasia.

The study concluded that the process aligns with the geophysical forces that characterise the region’s tectonically active interior - and rules out any connection to a particularly unusual source or nuclear test.

Dr. Fernando said: “Seismic waves carry information about the earthquake that produced them as they propagate around the planet.

"By recording the waves at different points on the Earth’s surface, we can work out what the properties of the source that produced them were.

“In this case, the source was what we call a reverse fault - a motion associated with the Earth’s crust being crushed as the Arabian and Eurasian plates collide.

"Nuclear tests have very different signatures, which are explosive.”

He says historical seismic data further supports the conclusion.

The Comprehensive Test Ban Treaty Organisation (CTBTO), which monitors nuclear tests worldwide, reported that earthquakes with similar characteristics and magnitudes occurred in the same region in 2015 and 2018 - both unrelated to nuclear activity.

Despite scientific evidence of natural seismic activity, claims that the earthquake was a nuclear test began spreading rapidly on social media just 17 minutes after the event.

Dr. Fernando said initial tweets misinterpreted seismic data, which soon gave way to misinformation and likely active disinformation.

The first suggestion that it was a nuclear test appeared on Twitter/X just 27 minutes after the earthquake.

Misinformation quickly escalated, with some posts citing seismic data from an entirely different earthquake in Armenia earlier that day to substantiate the nuclear test narrative.

The misinformation gained traction as conspiracy theories linked the Iranian earthquake to a supposed seismic event in Israel the same evening.

While the research team noted that it is difficult to confirm deliberate disinformation, they say the "sustained" engagement and specialized use of seismology data on social media suggested potential human authors with expertise.

The team found that one of the most widely shared posts promoting the nuclear test theory came from an account tied to Russian-supported disinformation campaigns.

Within hours of the quake, the false narrative moved from social media to news reports worldwide.

Indian English-language media were the most active in reporting the nuclear test claims, often referencing each other’s stories, and citing the incorrect seismic data.

The researchers also identified media reports from the UK, United States, Israel, Pakistan, Zimbabwe, and France.

The team recommended greater rapid-response collaborations among seismologists to quickly fact-check and correct misinterpretations of data, and to more actively counter misinformation.

Study co-author Dr. Saman Karimi, a Johns Hopkins geophysicist, said: “Scientific agencies could issue detailed reports swiftly to counter misinformation."

She added: “Giving amplification to contents coming from verified scientific accounts could help reduce the misleading narrative.

"This can be done via partnership between social media platforms and trusted seismologists or agencies such as the US Geological Survey.”