Japan's vaunted alert system runs up against limits

By Shingo Ito

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Jolted awake at 1:30 this morning by the Shimane quake, worked just fine.

No hint of any early warning system, though, either before or after.

-1 ( +2 / -3 )

In Japan, we have the J-Alert system. In the US, they have the NO alert system.

7 ( +9 / -2 )

If you're right at, or near the epicenter, the alarm may not reach you in time. We had a 5+ on Awaji in April 2013,

the quake was almost over when my phone went off. In contrast, in Tokyo in 2011-2013 when they were still having a lot of tremors (many centered in Ibaraki Minami) I got 10 seconds or so of warning, due to distance.

1 ( +3 / -2 )

“Runs up against limits” is the euphemistic way of saying that the system does not work.

-7 ( +1 / -8 )

'Runs up against limits' is a perfectly reasonable expression.

The earthquake warning is triggered by faster-moving but harmless P-waves, which arrive at the sensor before the slower-moving but destructive S-waves. If the sensor is very close to the epicentre then the difference between the arrival times of the two types of waves is too small to be useful.

Therefore, even with the best engineering in the world, the system runs up against limits imposed by the laws of physics.

6 ( +7 / -1 )

Warning announcement of earthquakes bother me very much interrupting radio programs I am enjoying.

-2 ( +1 / -3 )

Schopenhauer - how thoughtless of them!

1 ( +2 / -1 )


“Runs up against limits” is the euphemistic way of saying that the system does not work.

Worked pretty well down here in Kumamoto a couple of years ago. No system is perfect, yet those precious few seconds can mean the difference, especially if you are a little ways form the epicentre.

2 ( +2 / -0 )

I am in Tottori.

Two hours before the quake my cat was skittish and looking for a place to hide. She beats out any J-Early warning system. Was the same when we lived in Tokyo for all of those aftershocks in 2011.

2 ( +2 / -0 )

Schopenhauer: "arget of angers of Korean people is now directed to their own politicians - digging scandals of the ex presidents. This is their usual practices. Glad their arms changing from Japan."

You contradict yourself. How can it be "their usual practices (sic)", but "now" have "changed"?

In any case, what you should be focussed on is how corrupt politicians in SK get what they deserve, unlike in Japan -- since you bring it up -- where they just rig another election, win, and say it's the will of the people that they not be punished. All you're proving is that South Koreans don't take the same BS people here willing bend over for. So, keep it up! But cities also have to warn residents via the loudspeakers system they have if there are any serious threats.

1 ( +1 / -0 )

The thing I hate is game shows on tv that use an alarm sound to seem interesting, sending me running to my shelter.

@Peladon. interesting about the cat, heard this many times.

0 ( +0 / -0 )

I have never heard about the cat in Japan but "namazu" catfish is believed to be very sensitive about earthquakes and foretelling earthquakes happening by making strange moves before the earthquakes. Kashima shrine in Ibaraki Prefecture enshrines the catfish and Tokai University in Shizuoka Prefecture is famous about the study of the catfish and its relations to the earthquakes.

0 ( +0 / -0 )

In Japan, we have the J-Alert system. In the US, they have the NO alert system.

I have a weather alert radio that automatically goes off for any emergency in the area. There are loud public sirens which are hard to miss if outdoors, but they don't say WHAT the issue might be. If it isn't exactly noon and I hear those sirens, it is time to turn on the radio.

I could be notified about these things on my phone, but choose not to be bothered that way. I block SMS and don't have a data plan, so it wouldn't work anyway.

We've lived through 3 very near tornadoes (200m) and few dozen earthquakes.

1 ( +1 / -0 )

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