M 7.4 earthquake – 100 km ENE of Miyako, Japan

https://earthquake.usgs.gov/earthquakes/eventpage/us6000sri7/

by Someone • 3 months ago

292 123 3 months ago

earthquake.usgs.gov

tristanj• 3 months 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.

klempner3• 3 months 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.

athrowaway3z• 3 months ago

For anyone interested as i was. The Fukushima disaster was the result of a 9.1

uncognic• 3 months ago

And the fact that it is exponential, meaning that a magnitude 9 earthquake is more than 1000 times stronger than a magnitude 7

pezezin9• 3 months 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

whatsupdog• 3 months ago

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

asutekku2• 3 months 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.

fungi• 3 months 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.

pezezin9• 3 months ago

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

forbiddenvoid• 3 months ago

I was just in Aomori this past week (to see the sakura blossoms in Hirosaki). We literally left Sunday night, and while it seems like there really wasn't any concern in the city, I'm not sure I would have been prepared as a visitor to the country.

donw• 3 months ago

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

mkl• 3 months ago

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

dkural• 3 months ago

Some of the Istanbul earthquakes felt like that for me.

piazz2• 3 months 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/

kzrdude• 3 months ago

How do you use your 45 seconds?

piazz2• 3 months 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.

klempner3• 3 months 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)

nilslindemann• 3 months ago

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

gosub100• 3 months ago

Stop any trains. Open elevators at nearest floor.

Danox• 3 months ago

If you are in a precarious position at the time 45 seconds can make all the difference a California resident.

cloudbonsai• 3 months ago

How do you use your 45 seconds?

There is actually a clear, concise and actionable answer to this question:

- Hide under the nearest table or desk (if you are at home or in the office).

- Grab the nearest pole or handrail (if you are on a train).

The basic idea is that the most common cause of death in an earthquake is being crushed by falling objects, so you should use every second to minimize the risk.

Here are a few common mistakes:

- Do not attempt to stop furniture from falling (you'll get crushed by it)

- Do not try to run outside (you'll get hurt by falling walls)

- Do not try to turn off the gas (most systems have automatic shutoffs)

- And for Catfish's sake, do not use your precious 45 seconds to open the social media.

konart• 3 months ago

NERV

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

roer• 3 months 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.

Aboutplants• 3 months 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

strangegecko2• 3 months 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.

petterroea• 3 months 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

procflora• 3 months ago

Earthquake early warning systems are a top 10 peak human achievement in my book. No joke, I tear up watching videos of Japan's EEW system alerting people of possible danger just in time.

There are streamers who's whole thing is watching these alerts and setting up bobbleheads and glasses of water and stuff to show the shaking. It's so so so cool. Look at what we can do for each other you guys :')

https://www.youtube.com/watch?v=imH-ZyXwX5Q

Tor3• 3 months 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.

bell-cot• 3 months ago

Felt it all the way in Tokyo!

How many stories above the ground, and might you guess at your building's construction (wood frame, steel frame, etc.) and foundations (on bedrock, on loose sediments, etc.)?

Xenoamorphous• 3 months ago

Receiving one of those sounds really scary.

ricardobayes2• 3 months ago

Hmm, why does this needs to be an app and not the built-in alert notification system? Outsourcing critical infrastructure and emergency services to private parties is always a terrible idea.

pamcake• 3 months ago

Outsourcing critical infrastructure and emergency services to private parties is always a terrible idea.

That would include Apple and Google.

jandrewrogers• 3 months ago

In many countries the authority and capability to send alerts is relatively decentralized and/or they require people to be inserted in the decision loop. Things are this way for policy and jurisdictional reasons. To change it you'd need to redesign the bureaucracy and authority, including many parts that have nothing to do with emergency services. Those changes are not going to happen.

Under these constraints it is effectively impossible to send automated alerts at scale with low latency as demonstrated here. A private app does not operate under such constraints.

klausa2• 3 months ago

There's things built into iOS and Android and the government does send them; but not for _every_ quake, only for the bigger ones, and if you're close to epicenter.

This wasn't big enough in Tokyo to send out one.

spike0212• 3 months ago

In California I was recently alerted to a quake both by iOS (government issued alert) and the MyShakes app.

For major quakes I think over communication is probably warranted.

pezezin9• 3 months ago

It is built-in, broadcasted by the cell network itself:

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

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

swang2• 3 months ago

An Earthquake happened in SF recently where I got a push notification from Apple/iOS and I felt it maybe 5-10 seconds later. Nothing fancy though just a notification. I'm guessing it's not on for Japan? Seems like this app shows way more.

klausa2• 3 months ago

For big enough quakes you get notification from the government (a VERY loud and specific one too, being in public and hearing _everyones_ phones suddenly go off is... mildly terrifying) too; but they're so frequent and (usually) non-super-threatening that they don't get sent out for _every_ quake.

rconti2• 3 months ago

"not on for japan?" Are you expecting to have gotten a notification in SF for an earthquake in a place a 12 hour flight away? That sounds like annoyance, not a feature.

We also have the MyShake app here in CA, but I don't recall getting a notification through it for the last quake. I was asleep, though, so my memory is hazy.

numpad02• 3 months ago

All phones with 4G/5G worldwide should have it. They managed to make the broadcast push SMS thing used for the alerts a mandatory requirement for phones.

The broadcast warning from Japanese equivalent of NOAA don't get issued to areas where the peak acceleration is expected to be less than Shindo 4 level. So GP probably had 3 or less.

Shindo is peak and Magnitude is an integral, so these two can be wildly apart, and Shindo is more commonly used in Japan since buildings tend to be more resistant to longer events with lower peak intensity.

thomascountz• 3 months 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...

CodeCompost• 3 months ago

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

azepoi• 3 months ago

It is not. It's the moment magnitude scale

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

felixding• 3 months 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.

floxy2• 3 months ago

Is there a disproportionate frequency of earthquakes in Japan? My mental model is that there would be a uniformish distribution of earthquakes all around the Pacific ring-of-fire. But even living in a U.S. state with a Pacific Ocean border (and tsunami warning signs all along the coastal towns), it still seems like Japanese earthquakes outnumber local ones by a wide margin (especially for bigger ones like M7.0+). This could also be explained because Japan has a much higher population density, so earthquakes make headlines easier. And the devastating earthquakes in 2011 could make people more sensitive to earthquakes in Japan. But I guess my question is partially answered by a map of earthquakes on the Wikipedia page about the ring of fire:

https://en.wikipedia.org/wiki/Ring_of_Fire#/media/File:EQs_1...

...where is does seem like the West Coast of the North America has lower quake frequency. Here's to hoping the Cascadia subduction zone remains quiet for a while longer.

eigenform2• 3 months ago

No reason that the rate of subduction has to be the same everywhere. Some of the plate boundaries might be moving into each other in different directions too, the coupling between plates is not necessarily the same everywhere.

Anyway, in the case of Cascadia, remember that the lack of big earthquakes over the past 100 years is probably telling you that we just happen to live in a time where strain is accumulating (D:)

vaylian• 3 months ago

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

left-struck• 3 months 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• 3 months 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.

budududuroiu• 3 months 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• 3 months 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.

ursuscamp• 3 months ago

My brain is so cooked that I saw “M 7.4” and the first thing I thought was, “Which model is that?”

ngruhn• 3 months ago

It's quite mid on the benchmarks. No where near the SOTA earthquakes.

alfg• 3 months ago

I live in Tokyo in a 2 story house. Felt it swaying quite a bit for a few minutes.

eigenform2• 3 months ago

afaict part of the messaging behind this quake is about the worry that big Sanriku earthquakes like this might make it easier for the northeast part of the trench to unlock (closer to Aomori and Hokkaido, where the Japan Trench starts turning into the Kuril Trench).

M 7.4 earthquake – 100 km ENE of Miyako, Japan

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