> 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.

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.

It is not. It's the moment magnitude scale

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

The USGS can still help you find oil and gold though.

Because?

Here you have the same earthquake, but reported by Japan: https://www.data.jma.go.jp/multi/quake/quake_detail.html?eve...

As a European, I feel fine that American and Japanese governments report on this.

Well you could read the japanese reports, but they'd be in japanese

Japan has their own communication platforms for this, they're not relying on a US government site. I'm in Japan on vacation, and I got notified of the earthquake within a minute of it happening on the NERV app, which is a common disaster alerting app here.

The US monitors things like this because tsunami danger to the west coast is a real if remote possibility.

Here you go: https://earthquake.tenki.jp/bousai/earthquake/detail/2026/04...

Japan also obviously also monitors this.

https://nerv.app/en/

This kind of data is actually shared by governments with each other as well.

Science has no borders, much less disasters.