Two minor quakes 'wrongly trigger' Japan's alert system
Tokyo: Millions of people in Tokyo received a loud alert on Friday that a "strong" earthquake was about to hit –but it proved to be a false alarm apparently triggered by geological chance.
Text messages and whooping alarms were sent to the phones of millions in and around the Japanese capital, warning: "A quake has occurred off Ibaraki. Prepare for strong jolts."
But officials suspect the early alert, issued by the Japan Meteorological Agency, was triggered by two minor earthquakes hitting the archipelago at nearly exactly the same time.
A 4.4-magnitude quake struck off Ibaraki, northeast of Tokyo, in the Pacific at 11:02 am (0202 GMT).
And nearly simultaneously, a 3.9-magnitude tremor hit Toyama prefecture, some 350 kilometres (217 miles) west of the one off Ibaraki.
Even Prime Minister Shinzo Abe was caught off-guard by the false alarm –with TV footage showing him checking his flip phone as alarms echoed in the prime minister's office ahead of a cabinet meeting. An alert also flashed on public broadcaster NHK as its announcer warned viewers: "Protect yourself. Stay away from unstable furniture."
The warning forced train and subway operators in the capital to suspend services temporarily, while elevators –including those of Tokyo Tower –stopped, local media reported.
But any jolts were moderate with no injuries or damage reported. "We suspect that the system overestimated it by calculating the two separate quakes as one big quake," an official said, adding that the agency was further investigating the cause.