M 7.4 earthquake – 100 km ENE of Miyako, Japan

Felt it all the way in Tokyo!

There is this amazing app called NERV that, whenever there is a large earthquake anywhere in Japan, sends you an early warning push notification and an animated display with shockwaves emanating from the epicenter, plus a countdown timer for the first wave hitting you. The first it went off for me it felt like something out of sci-fi. I think I got 45 seconds this time before my apartment started shaking.

https://nerv.app/en/

The earthquake magnitude was revised up to a 7.7

No major tsunami is expected, local media reported initial waves were recorded as high as 40cm. The Japan Meteorological Agency forecasted up to 3m (10ft) waves.

I don't believe this earthquake is a big deal. Large earthquakes (M7.0+) happen in Japan several times a year, and given this happened in the middle of the ocean, I don't expect any major damage.

I live in Aomori (Northernmost prefecture of Honshu) and we got the warning before the earthquake arrived by all the cellphones in the office going crazy at the same time. It was kind of funny, because we have a lot of new guys here who have never been to Japan before and it was their first earthquake ever xD

I live in Tokyo. Today's quake felt pretty strong (maybe because I was on the 14th floor) and lasted a while. Haven't felt one this big in months.

How long do these earthquakes typically take until they are over?

Ruby Kaigi[1] starts soon in Hakodate, across the Tsugaru Strait in southern Hokkaido, ~200–250 km away. I hope everyone stays safe.[2]

[1]: https://rubykaigi.org/2026/

[2]: https://www.japan.travel/en/japan-safe-travel-information/ts...

This one was weird, too, like being on a boat in mildly choppy water, not a violent shake at all.

Is this the Richter scale? I thought it was obsolete.

Felt it all the way in Tokyo!

https://nerv.app/en/

45 seconds is an incredible accomplishment. That’s a decent amount of heads up to get safer place. Obviously nerve wracking but great progress in alerts

>NERV

Does it play appropriate Evangelion OST track depending on magnitude though?

I didn't feel a thing a bit south of Nagoya. Almost strange that there was nothing here, when you got shaking in Tokyo.

How do you use your 45 seconds?

45 seconds is an incredible accomplishment. That’s a decent amount of heads up to get safer place. Obviously nerve wracking but great progress in alerts

It sounds impressive but it's worth considering that this was a large quake that was felt by basically half of the country. You do not get this much warning if you are anywhere near where damage happens.

The 45 seconds is better thought of as the time it takes for the quake to propagate to Tokyo

Yeah. That's leagues better than what I get in Taiwan. The alert often arrives when the building is shaking or even after. I've never had a meaningful headstart.

Ruby Kaigi[1] starts soon in Hakodate, across the Tsugaru Strait in southern Hokkaido, ~200–250 km away. I hope everyone stays safe.[2]

[1]: https://rubykaigi.org/2026/

[2]: https://www.japan.travel/en/japan-safe-travel-information/ts...

I live in Tokyo. Today's quake felt pretty strong (maybe because I was on the 14th floor) and lasted a while. Haven't felt one this big in months.

The earthquake magnitude was revised up to a 7.7

No major tsunami is expected, local media reported initial waves were recorded as high as 40cm. The Japan Meteorological Agency forecasted up to 3m (10ft) waves.

I don't believe this earthquake is a big deal. Large earthquakes (M7.0+) happen in Japan several times a year, and given this happened in the middle of the ocean, I don't expect any major damage.

Yes, this is definitely only a medium deal, given that the tsunamis were mild. There is the usual concern that it might be a foreshock for a bigger quake but that's fairly unlikely.

Plenty of disruption (including a bunch of the shinkansen lines) and annoying evacuation up on the coast.

I will say that this was the longest swaying I've felt in my Kawasaki tower mansion apartment since moving here three years ago -- things were still moving about 5 minutes after it started.

was reading in a park in suburban tokyo a few years ago, notifications arrived for the noto peninsula earthquake.

kids in the park stared doing wobbly knee dance :D

felt the quake about 30sec later.

How much warning did you get? I mean in minutes or seconds?

This one was weird, too, like being on a boat in mildly choppy water, not a violent shake at all.

In my experience (NZ) that means it was strong but distant.

How long do these earthquakes typically take until they are over?

Is this the Richter scale? I thought it was obsolete.

I’m Chiba so pretty far away from this one, and in this case it was like a real low frequency swaying that lasted maybe 3 minutes or so.

In the past there were small earthquakes closer to me that felt like quite a violent bump followed be higher frequency vibrations, but less than a minute. Those earthquakes were much smaller though, like magnitude 4.

It is not. It's the moment magnitude scale

https://en.wikipedia.org/wiki/Moment_magnitude_scale

The 45 seconds is better thought of as the time it takes for the quake to propagate to Tokyo

I didn't feel a thing a bit south of Nagoya. Almost strange that there was nothing here, when you got shaking in Tokyo.

How do you use your 45 seconds?

At 45 seconds, load up social media. (although I actually missed the warnings this time, was focused on work) At least assuming the number is only 7.x.

If it were 8+ or somewhat closer, I'd get under my desk. (then pull up social media on my phone)

If it's a big one and it's near you, you'd move away from the windows and heavy things that can fall, I suppose?

For me I always just turn on iPhone screen recording and marvel at this amazing app and wish we had something like this in California.

Stop any trains. Open elevators at nearest floor.

>NERV

Does it play appropriate Evangelion OST track depending on magnitude though?

It is straight up the same NERV, so it might.

From the site:

> The name and logo of "NERV" are used with the explicit permission of khara Inc., the copyright holder of the "Evangelion" series, and Groundworks Corporation, which manages the rights to the series.

Yes, this is definitely only a medium deal, given that the tsunamis were mild. There is the usual concern that it might be a foreshock for a bigger quake but that's fairly unlikely.

Plenty of disruption (including a bunch of the shinkansen lines) and annoying evacuation up on the coast.

I will say that this was the longest swaying I've felt in my Kawasaki tower mansion apartment since moving here three years ago -- things were still moving about 5 minutes after it started.

In my experience (NZ) that means it was strong but distant.

I’m Chiba so pretty far away from this one, and in this case it was like a real low frequency swaying that lasted maybe 3 minutes or so.

It is not. It's the moment magnitude scale

https://en.wikipedia.org/wiki/Moment_magnitude_scale

was reading in a park in suburban tokyo a few years ago, notifications arrived for the noto peninsula earthquake.

kids in the park stared doing wobbly knee dance :D

felt the quake about 30sec later.

The one in 2024? I was in Tokyo at that time but we didn't get any notification nor felt anything :/

How much warning did you get? I mean in minutes or seconds?

If it's a big one and it's near you, you'd move away from the windows and heavy things that can fall, I suppose?

For me I always just turn on iPhone screen recording and marvel at this amazing app and wish we had something like this in California.

Stop any trains. Open elevators at nearest floor.

Depends on the location, the alert comes usually as soon as the initial tremors are registered. If you're at the epicenter, tough luck. For example, for me in Tokyo, the alert came 2 minutes before it hit, and even then, the actual earthquake was extremely subtle.

Yeah. That's leagues better than what I get in Taiwan. The alert often arrives when the building is shaking or even after. I've never had a meaningful headstart.

I usually get it a few seconds ahead of time at least, in Taipei. I figured it's more related to the proximity than anything else.

At 45 seconds, load up social media. (although I actually missed the warnings this time, was focused on work) At least assuming the number is only 7.x.

If it were 8+ or somewhat closer, I'd get under my desk. (then pull up social media on my phone)

Standing underneath a doorframe is also advisable.

It is straight up the same NERV, so it might.

From the site:

This is just the best. A very serious company, doing seriously cool and important stuff, also has an anime name/icon.

I wish more corps took themselves so lightly, while remaining serious about what they do.

The one in 2024? I was in Tokyo at that time but we didn't get any notification nor felt anything :/

I usually get it a few seconds ahead of time at least, in Taipei. I figured it's more related to the proximity than anything else.

Standing underneath a doorframe is also advisable.

I'm pretty sure that is advice from the last millennium that is no longer taught.

This is just the best. A very serious company, doing seriously cool and important stuff, also has an anime name/icon.

I wish more corps took themselves so lightly, while remaining serious about what they do.

For people unfamiliar wanting an easier comparison, Evangelion is Japans star wars. It'd be like learning of tornadoes from someone with Empire insignia

Sadly we're stuck with companies naming themselves things like "Melchior" and "Palpatine" and somehow it's a good thing?

Anyway I need to get back to working on the Torment Nexus.

In our case I guess we got the warning 10~20 seconds before the earthquake? I don't know, I didn't count it xD