90,000 people advised to take shelter after 7.5-magnitude quake, but tsunami warnings downgraded

  • pelespirit@sh.itjust.works
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    3 months ago

    Does anyone know if this is the US scale or the Japanese scale and how they compare? I tried to look it up but it’s very confusing.

    • mbfalzar@lemmy.dbzer0.com
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      3 months ago

      The 7.5 magnitude is the one both the US and Japan use, but if you meant the seismic intensity scale that Japan uses, this one was an upper 6 in Aomori per the article, because the seismic intensity scale is based on actual conditions in specific locations. Upper 6 means strong enough to knock over people and move heavy furniture, but two miles away it could be a 5 on the intensity, because the intensity scale is the effect it has on where you are. It’s the same 7.5 magnitude earthquake, but the felt intensity is different depending on where you are

      • pelespirit@sh.itjust.works
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        3 months ago

        Thank you for explaining that. I was trying to figure it out from wikipedia and another scale, and I left more confused. I found the chart for what you’re saying is the seismic intensity, but then they said it could be an 8 and there was no 8 on that chart, lol.

      • tigeruppercut@lemmy.zip
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        3 months ago

        Only one city registered an upper 6 (Hachinohe), but there were plenty of lower 6 and upper 5s in the area. To show your point about intensities in different locations, you can see from this map that places just outside the immediate area (Hokkaido and the opposite side of Aomori from where the quake was centered), numbers ranged from lower 5s to 3s, and 3s can also be seen down the coast as far as tokyo hundreds of km away.

    • altphoto@lemmy.today
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      3 months ago

      I once jumped a book with 7 stories in it. It was a huge jump! I mean, normal houses are usually 2 or 3 stories! Imagine jumping over 7! And it wasn’t like I just barely made it. I was a kid, I got to running speed and that book never stood a chance. I bet I could even run over 7 Bibles.

      So yeah, what sort of scale are they using?