I get there has been a few 5s in Chiba lately, one of which set off the early warning system in Tokyo.
Given the magnitude / Shindo scale was similar with this earthquake and the early warning earthquake a couple of weeks ago… I am wondering why it wasn’t triggered this time? Does anyone know what other features the early warning system looks for before sending out an alert?
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The early warning system did go off, I was watching TV. If you are in Tokyo you wouldn’t received the warning by phone because Tokyo wasn’t predicted to have strong shaking.
It’s not magic – https://earthquake.ca.gov/how-it-works/
The system isn’t infallible. It’s calculating and relying data within an extremely narrow window of time, after all. Consider any warning you get to be a bonus, because it absolutely is. I speak as someone who’s strongest earthquake experience is still outside Japan, which lead to far more widespread damage than the equivalent would here.
Mine didn’t go off because I disabled it after last time
In Chiba, early warning system went off about 10 seconds before the quake for me.
I am in the west of Saitama and my alarm did go off even though I could barely notice any shaking, yet friends in Tokyo are saying theirs didn’t go off. The system just isn’t all that reliable (which is to be expected).
The alarm is programmed to go off when you’re sleeping and at risk of not noticing it.
There’s no fun in warning people when they’re already awake and alert.
Diiiiiiiiiiiidnt even feel it. Only way I realized is that the trains stopped in the station for a while.
I got the warning a few seconds in advance also in Chiba-ken.
Every phone on my train carriage went off.
I was watching NHK up here in Hokkaido and it went off
Tbh, if it’s a strong earthquake, wat is an early warning system going to do 🤷🤔😂
[Was your phone on?](https://www.reddit.com/r/japanlife/comments/13eanim/not_receiving_earthquake_alerts_when_phone_is/?utm_source=share&utm_medium=ios_app&utm_name=ioscss&utm_content=2&utm_term=1)
The alarm on your phone only goes off if you are in an [area](https://www.data.jma.go.jp/svd/eqev/data/joho/shindo-name.html) where EEW for the general public has been issued.
Today it was only in Chiba, Ibaraki, and Saitama **(south)**.
**When an earthquake with maximum intensity 5- or higher is expected to occur,** EEW for the general public will be issued in areas where intensity **4** ~~5-~~ or higher is expected.
Edit: **bold** text
Looks like ‘The Big One’ is finally at your doorstep.
I remember there was a member here who posted about being worried about Earthquakes living in Tokyo-shi due to anxiety, she must be reeling.