The Japan Meteorological Agency has cancelled an erroneously issued 9.9 magnitude earthquake warning that briefly hit areas from northern to central Japan. The alert caused panic among the population and disruptions to public transport.
The agency said its computer system had incorrectly determined the epicentre and strength of the earthquake. The initial warning indicated that the quake was in the Kuril Islands region off the Japanese island of Hokkaido. About eight minutes after it was issued, the warning was cancelled.
It was later confirmed that the actual earthquake had a magnitude of 6.9 and occurred near the Russian Kamchatka Peninsula, at a depth of about 160 kilometres. A maximum seismic intensity of 1 was recorded in Hokkaido, but the strong shaking that the initial alert warned of did not occur.
“We deeply apologize for the inconvenience caused“, said Ayataka Ebita, director of the agency's earthquake and tsunami monitoring department. He said there was no evidence of an external cyberattack, and the most likely cause was a problem with the processing of information by computer software.
The false alert brought back memories of 2011.
The alert was particularly worrisome given Japan's seismic history. In 2011, a magnitude 9 earthquake triggered a powerful tsunami that killed about 18,500 people. The disaster also caused severe damage to the Fukushima nuclear power plant.
The latest incident did not have comparable consequences, but it showed how quickly an automatic signal can affect transportation and daily life in a country where earthquake warnings are part of the civil protection system. The Japan Meteorological Agency is continuing to clarify the reason for the incorrect assessment of the epicenter and magnitude.
Sources: btvnovinite.bg, nippon.com, japantimes.co.jp