The Meteorological Agency issued a false alarm shortly before 5 p.m. Thursday, warning that a strong earthquake was about to hit Nara and Osaka prefectures. It turned out to be a mild tremor.
The agency said the false alarm was triggered by some noise trouble that occurred in an underwater earthquake scale off Mie Prefecture.
“We apologize for causing problems to so many people,” said Toshihiko Hashida of the agency during a press conference.
“But we want to ask everyone to make the effort to secure their safety when an alert is issued, because it is a fact that there is some kind of temblor when the alarm is sent,” he said.
The alert, issued at 4:56 p.m., is only supposed to go off for a quake with an intensity of at least lower 5 on the Japanese scale to 7. The alarm was sent to a wide swath of Japan from the Kansai region to Kanto, as well as Kyushu.
The agency said it did detect an earthquake measuring magnitude 2.3 centered in northern Wakayama Prefecture, but it registered no earthquake more than intensity level 1 on the Japanese scale outside the immediate vicinity. The agency had estimated the quake’s magnitude at 7.8 when it had sent the alert.
A resident of Ikoma in northern Nara Prefecture contacted by The Japan Times said she felt no shaking.
Central Japan Railway Co. (JR Tokai) said its bullet trains halted between Odawara and Shin-Osaka stations but resumed about 10 minutes later.
JR West also said that the alert halted 38 lines in the Kansai region, although all trains resumed operations by 5:10 p.m. A total of 228 trains were delayed because of the alarm, which affected about 120,000 passengers, it said.
Other train services in the region also made an emergency stop when the alert sounded, but they resumed service about 10 minutes later.