On the 16th, the Japan Meteorological Agency overestimated the magnitude in an Earthquake Early Warning, from 6.9 to 9.9, and cancelled the warning. TBS's news23 reported that the agency held three press conferences the same day and apologized. The program put the cause down to two errors. Keitai Watch reported that the 16th's warning had been a false alarm and that its cause had come to light. The agency is reported to have made an urgent correction. The specifics of the two errors are not shown in the coverage we could confirm this time. That the agency's press conferences were split into three on the same day is also reported as part of the course of the apology. The cancellation of the warning is a response TBS described as “unusual.”
People who received the warning may have been pressed to act on the assumption of a giant earthquake that had not actually occurred, and equipment that stops automatically, such as railways and factories, is easily affected. When cancellations pile up, trust in genuine warnings also falls. Unless inspection of the delivery routes goes ahead on the very day the confusion occurs, users will not be able to tell the difference if the next false alarm takes the same form. Companies and schools that have automatic systems to stop equipment on receiving a warning need to set recovery procedures for false alarms as well.
Check the notification settings for Earthquake Early Warning on your smartphone, and share with your family that a cancellation notice can appear even when you feel no shaking. Use this opportunity to check your evacuation site and the securing of furniture. At home and at work, write down and post what to do on receiving a warning (get under a desk, shut off fires, secure an exit). Even when a cancellation notice comes, stay alert for aftershocks and real shaking for a few minutes.
The question is whether the device side could have had a mechanism to suspect an anomaly once the figure exceeded reality. The responsibility for the false alarm lies not only in the overstated figure but in the anxiety users bore during the minutes before the cancellation.
TBS NEWS DIG, Keitai Watch, Asahi Shimbun
False M9.9 Earthquake Early Warning: Japan Meteorological Agency Cancels It and Apologizes at Three Press Conferences
In the Earthquake Early Warning delivered on the 16th, the magnitude was overestimated from 6.9 to 9.9, and the warning was cancelled. The agency explained the cause as two errors and apologized.
On the Earthquake Early Warning it announced on the 16th, the Japan Meteorological Agency saw its estimated magnitude jump sharply from the initial 6.9 to 9.9, and then cancelled the warning itself in an unusual step. TBS's “news23” reported that the agency admitted it had overestimated and held three press conferences the same day to apologize. A magnitude of 9.9 exceeds that of any earthquake in recorded history, so a value of a scale that cannot occur in reality was sent out as a warning. The program's headline picked up on the point that the magnitude was shown as 9.9.
As for the cause, the program reported that there were “two errors.” Keitai Watch reported that the cause of the false alarm in the 16th's warning had come to light and that the agency had made an urgent correction. The specifics of the correction, and at which stage of processing each of the two errors occurred, are not detailed in the coverage we could confirm this time; we are waiting for a detailed explanation from the agency. Keitai Watch's article presents it as the cause of the false alarm having come to light, and reports the agency's urgent correction.
TBS characterized the cancellation as “unusual.” The sequence was that only the magnitude figure was sharply rewritten after the warning went out, and in the end the entire warning was withdrawn. Coverage also takes up, as a sign of how seriously the apology was meant, the fact that the agency did not stop at one press conference but held three within the same day. However, the areas where shaking was forecast in this warning, and the number of people who actually received the notification, do not appear in the coverage we could confirm this time.
Separately, the Asahi Shimbun reported on the night of the 17th that the response to the NTT Docomo malfunction, in which Earthquake Early Warnings were not delivered, had been completed. Two problems pointing in opposite directions, a false alarm and a missed delivery, thus surfaced in the same week. No technical connection between the two has been reported at this point, and no basis for linking them has been shown. The timeline of at what stage the agency noticed the anomaly, and how many minutes it took to cancel, is likewise not shown in current coverage. The results of the verification are best confirmed in the agency's official announcements.
The Earthquake Early Warning is a system for prompting people to take protective action before strong shaking arrives, and the reliability of the information itself is the premise of its function. With cancellations and apologies piling up, the focus is on how recipients will take it. The next points to check are the content of the recurrence-prevention measures the agency announces and the results of inspections of delivery routes, including the mobile carriers.
A Japan Meteorological Agency alert that catches the first tremors of an earthquake and gives notice before strong shaking arrives.