Japan issues false magnitude 9.9 earthquake alert, apologises after withdrawing warning

Tokyo: Japan's meteorological agency has apologised after mistakenly issuing an alert for a massive 9.9-magnitude earthquake near the Kuril Islands, triggering emergency warnings on millions of mobile phones and briefly disrupting public transport.

The Japan Meteorological Agency (JMA) withdrew the alert within minutes on Friday after discovering an error in its earthquake calculations.

The agency initially reported that a powerful earthquake had struck near the Kuril Islands, known in Japan as the Chishima Islands. The warning prompted emergency notifications across the country, raising concerns about a potentially catastrophic seismic event.

However, the JMA subsequently clarified that the actual earthquake measured magnitude 6.9 and occurred near Russia's Kamchatka Peninsula shortly after midday. The tremor originated at a depth of approximately 160 kilometres.

"We deeply apologise for the significant inconvenience and concern caused to the public," JMA official Shinya Tsukada told reporters.

Although the false warning did not trigger widespread panic, it temporarily affected public transport services.

The agency attributed the mistake to an error in determining the earthquake's epicentre. According to officials, the initial magnitude calculation was based on the incorrect assumption that the epicentre was approximately 680 kilometres farther from Japan than its actual location.

The incident has drawn attention to Japan's earthquake early-warning system, which plays a crucial role in alerting residents to potentially destructive tremors.

Japan remains particularly sensitive to major earthquake warnings following the devastating March 2011 disaster, when a magnitude 9.0 undersea earthquake triggered a massive tsunami.

The catastrophe left around 18,500 people dead or missing and caused extensive damage to the Fukushima nuclear power plant, resulting in one of the world's worst nuclear disasters.

According to Japanese media reports, an earthquake measuring magnitude 9.9 would release approximately 22 times the energy generated by the devastating 2011 earthquake.

The erroneous alert was withdrawn before any major disruption occurred.