The Japanese government has unveiled a chilling AI-generated video illustrating the potential devastation Tokyo could face if Mount Fuji were to erupt.
The short but striking simulation shows volcanic ash spreading across the capital within just hours of an eruption. It begins with a woman receiving an emergency alert on her phone, before a stern narration warns: “The moment may arrive without any warning.”
Officials were quick to stress that there is no sign an eruption is imminent, but the video serves as a stark reminder that Mount Fuji remains very much an active volcano. Its last eruption, the Hoei eruption, took place more than three centuries ago in 1707.
How quickly ash could blanket Tokyo
According to the new government model, ash could reach Tokyo within two hours of an eruption. This would present severe risks to public health while also threatening to disrupt electricity, transportation, and even food distribution across one of the world’s most densely populated metropolitan areas.
The video was released to coincide with Japan’s Volcano Disaster Prevention Day, an annual event designed to raise awareness and encourage preparation. A separate government message urged residents to “visualise specific scenarios” so they can better understand how to respond in the event of a large-scale disaster.
A nation living with constant risk
Japan sits on the Pacific “Ring of Fire,” a region notorious for its seismic activity. The country regularly experiences earthquakes and volcanic tremors, and officials frequently warn of the importance of readiness. In January, the government estimated there is an 80 per cent chance of a severe earthquake hitting the southern Nankai Trough within the next 30 years.
Mount Fuji, which sits about 100km southwest of Tokyo, looms as one of the nation’s greatest potential natural threats.
Public reaction
Reactions to the video have been mixed. Some residents expressed unease at the chilling reminder of how quickly chaos could unfold. One X user wrote: “The thought of volcanic ash causing transportation chaos in the Tokyo metropolitan area is terrifying.”
Another added: “Cassette stove, flashlight, water, food … it would be hard to lose power during Japan’s sweltering summer.”
But others accused the government of fear-mongering. One user argued: “It tends to be used to stir up a sense of crisis and fear.”
The cost of catastrophe
Authorities have warned locals near Mount Fuji for years to remain prepared. In March, residents were advised to stock at least two weeks’ worth of essential supplies in case of an eruption.
Government projections paint a grim picture. A full eruption could produce 1.7 billion cubic metres of ash, with nearly 500 million cubic metres potentially piling up on infrastructure and roads. The fallout could collapse weaker buildings, halt train lines, block highways, and damage power grids.
The total economic impact is estimated at up to 2.5 trillion yen (USD$17 billion), a disaster Japan hopes it will never have to face, but one its people are being urged not to ignore.