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Palu supershear quake/tsunami Sept 2018

  1. Feb 4, 2019 #1

    jim mcnamara

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    Popular article: https://www.nationalgeographic.com/...hquake-supersonic-supershear-speed-indonesia/
    Nature.com paywall/abstract:
    https://www.nature.com/articles/s41561-019-0308-8

    After analysis of the quake centered near Palu Indonesia that killed 2000+ people, it was determined that the velocity at which the tremor propagated the tear in the earth, this was "no ordinary earthquake". It is termed a supershear event.

    Supershear refers to the velocity of propagation of the rupture. These are rare. This one had lots of seismogaphs listening. Maybe our @davenn can point out this phenomenon using his output as recorded on his machine.
     
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  3. Feb 4, 2019 #2

    davenn

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    They must be ! ... Supershear is not a term I have heard of before



    Hmmm, not sure how these would be manifest on a seismogram.
    My initial thought would maybe a higher frequency of the P ( and maybe also the S) waves due to the higher velocity of the propagation of the rupture.

    I would have to try and see if there is a difference in P wave frequencies of that event compared to others with a similar distance from my recorder.

    Dave
     
  4. Feb 4, 2019 #3

    jim mcnamara

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    If you can access Nature Geoscience, then I assume there is methodology in the primary article.

    [guess]The idea is that the point of emanation of the S-waves would be moving really fast relative to one station. It also mentions "bunching up" of multiple waves onto the wavefront.[/guess]

    So possibly it takes multiple stations to discern a rapidly moving location. The pop sci article mentions 9300 ft/s.
     
    Last edited: Feb 4, 2019
  5. Feb 6, 2019 #4

    BillTre

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