M 7.4 earthquake – 100 km ENE of Miyako, Japan

171

SSomeone about 6 hours ago 71 commentsRead Article on earthquake.usgs.gov

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Discussion (71 Comments)Read Original on HackerNews

piazz•about 4 hours ago

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/

Aboutplants•about 4 hours ago

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

petterroea•about 3 hours ago

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

strangegecko•about 3 hours ago

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.

philistine•about 2 hours ago

It would seem the forewarning depends a lot on the distance from the epicentre. This quake, for Tokyoites, was far enough from them that they could beat the earthquake's speed. I'm fairly certain the people on the East Coast near the quake got no notification ahead of the event.

sampullman•about 3 hours ago

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.

konart•about 4 hours ago

>NERV

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

roer•about 4 hours ago

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.

azath92•about 4 hours ago

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.

Tor3•about 4 hours ago

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

kzrdude•about 4 hours ago

How do you use your 45 seconds?

klempner•about 4 hours ago

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)

fennecbutt•about 3 hours ago

Standing underneath a doorframe is also advisable.

piazz•about 4 hours ago

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.

nilslindemann•about 3 hours ago

https://i.imgur.com/WJ0NM1J.png

gosub100•about 3 hours ago

Stop any trains. Open elevators at nearest floor.

tristanj•about 5 hours ago

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.

klempner•about 4 hours ago

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.

pezezin•about 5 hours ago

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

fungi•about 4 hours ago

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.

pezezin•about 4 hours ago

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

whatsupdog•about 5 hours ago

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

asutekku•about 4 hours ago

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.

pezezin•about 4 hours ago

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

felixding•about 4 hours ago

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.

thomascountz•about 4 hours ago

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...

budududuroiu•about 3 hours ago

Was in Tokyo today, if I didn't see the news, I wouldn't have noticed there even was an earthquake.

Surprised others said they felt it.

jhatax•about 2 hours ago

Didn’t feel it either, and my family and I are close to Shirokanedai. I hope folks are fine where this was felt more than what I experienced.

vaylian•about 3 hours ago

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

left-struck•about 3 hours ago

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 by higher frequency vibrations, but less than a minute. Those earthquakes were much smaller though, like magnitude 4.

kccqzy•about 2 hours ago

> The 1989 earthquake in Loma Prieta, California, which killed sixty-three people and caused six billion dollars’ worth of damage, lasted about fifteen seconds and had a magnitude of 6.9. A thirty-second earthquake generally has a magnitude in the mid-sevens. A minute-long quake is in the high sevens, a two-minute quake has entered the eights, and a three-minute quake is in the high eights. By four minutes, an earthquake has hit magnitude 9.0.

donw•about 4 hours ago

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

mkl•about 4 hours ago

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

CodeCompost•about 4 hours ago

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

azepoi•about 4 hours ago

It is not. It's the moment magnitude scale

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