• ProfessorScience@lemmy.world
    link
    fedilink
    English
    arrow-up
    4
    ·
    4 hours ago

    False alarms are certainly not good, but I have to imagine that delaying an alarm by even a few minutes to double check has got to be a tough call.

  • A_A@lemmy.world
    link
    fedilink
    English
    arrow-up
    6
    ·
    6 hours ago

    Richter scale
    https://en.wikipedia.org/wiki/Richter_scale
    Richter magnitudes

    10

    Seismologist Susan Hough has suggested that a magnitude 10 quake may represent a very approximate upper limit for what the Earth’s tectonic zones are capable of, which would be the result of the largest known continuous belt of faults rupturing together (along the Pacific coast of the Americas).[…ref…] A research at the Tohoku University in Japan found that a magnitude 10 earthquake was theoretically possible if a combined 3,000 kilometres (1,900 mi) of faults from the Japan Trench to the Kuril–Kamchatka Trench ruptured together and moved by 60 metres (200 ft) (or if a similar large-scale rupture occurred elsewhere). Such an earthquake would cause ground motions for up to an hour, with tsunamis hitting shores while the ground is still shaking, and if this kind of earthquake occurred, it would probably be a 1-in-10,000-year event.

    • mako@lemmy.today
      link
      fedilink
      English
      arrow-up
      2
      ·
      2 hours ago

      it would probably be a 1-in-10,000-year event.

      I’ve heard that before. Magnitude 10 earthquake confirmed by year-end.

  • ramble81@lemmy.zip
    link
    fedilink
    English
    arrow-up
    24
    arrow-down
    1
    ·
    9 hours ago

    If I understand it correctly a 9.9 would be 4 times stronger than the largest ever earthquake in history (Chile, 1960) and would be the same energy released as 712,000 nukes dropped in Hiroshima or 187 Tsar Bombas going off at once.

    I understand the pucker factor. The scale of those numbers is almost beyond mind numbing.

    • Mister_Hangman@lemmy.world
      link
      fedilink
      English
      arrow-up
      4
      ·
      1 hour ago

      From my understanding a 10.0 splits the planet and kills everyone on earth.

      So a 9.9 leaves fucking Evan from accounting alive and that’s it.

    • Deadrek@lemmy.today
      link
      fedilink
      English
      arrow-up
      2
      ·
      7 hours ago

      At those levels the people you’d need to warn would already be dead.

      Depending on where that quake happened and what kind, portions of Japan could become subterranean I imagine. Mother nature scary.

  • Stern@lemmy.world
    link
    fedilink
    English
    arrow-up
    18
    ·
    10 hours ago

    ngl if a 9.9 was revealed to not be real I’d be breathing a sigh of relief. It’d be the worst quake in recorded history.

  • pageflight@piefed.social
    link
    fedilink
    English
    arrow-up
    5
    ·
    9 hours ago

    No root cause for this one yet, but:

    Similar false alarms have occurred in the past. In July 2020, the JMA issued a warning to 15 prefectures, including Tokyo, after incorrectly estimating a quake’s location and overstating its magnitude.

    In August 2013, noise from a seabed seismometer was mistakenly combined with data from a small earthquake, triggering widespread false warnings across the Kinki region.

    • A_A@lemmy.world
      link
      fedilink
      English
      arrow-up
      1
      arrow-down
      1
      ·
      6 hours ago

      i misread “seismometer” as “sea monster”
      Godzilla !