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.

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.

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...

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

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