Japan's meteorological agency issued a magnitude-9.9 earthquake warning on October 16, only to withdraw it minutes later and issue a public apology. The Japan Meteorological Agency (JMA) sent out the alert at around noon local time (4am UK time), but cancelled it approximately eight minutes afterwards. A press conference was later held to apologise for the mistake.
Warning details and correction
The initial advisory said an earthquake had struck the Chishima Islands, off Hokkaido, with a maximum intensity of 7 on the Japanese seismic intensity scale. In reality, some areas experienced a tremor of intensity 1, the agency said. The exact cause of the error is still under investigation, but preliminary assessments suggest the warning system misread the data.
The actual earthquake registered a magnitude of 6.9 and struck near Russia's Kamchatka Peninsula at a depth of approximately 140 to 160 kilometres at around 12.39pm. A magnitude 1 tremor was detected in Hakodate, Hokkaido, but no strong shaking or tsunami risk was reported.
Apology and impact
Ayaki Kaito, head of the Earthquake Monitoring Division of the Japan Meteorological Agency, said: "We sincerely apologise for the inconvenience caused to the public." The warning initially said strong tremors would be felt in Hokkaido, Tohoku, and the Kanto region.
Due to the warning, several train services were cancelled, including bullet train services on the Tokaido Shinkansen Line, which were temporarily suspended between Shin-Yokohama and Toyohashi stations. Japan's earthquake early warning system detects tremors and issues a warning when a magnitude 5 or higher is predicted.
Context on strong earthquakes
The most powerful earthquake in history was a 9.5-magnitude tremor striking Valdivia in Chile on May 22, 1960. That tremor killed at least 1,655 people, injured 3,000 and displaced two million, as well as causing some $550 million in damage in the country. It also prompted a tsunami, which reached as far as Hawaii, Japan and the Philippines.
