Hawaii volcanics

Discussion in 'Fred's House of Pancakes' started by tochatihu, May 4, 2018.

  1. tochatihu

    tochatihu Senior Member

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    Quite a large increase in aerial coverage by lava and number of houses taken.

    Guatemala has a much more acute and fatal problem with a stratovolcano.
     
  2. fuzzy1

    fuzzy1 Senior Member

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    Guatemala's pyroclastic flows apparently ran about 50 mph, making them much deadlier than the slow creeping Hawaiian lava.

    Similar pyroclastic events elsewhere have flowed upwards of 400 mph. Such an event destroyed Saint-Pierre, Martinique, in 1902, killing around 30,000 people.
     
  3. tochatihu

    tochatihu Senior Member

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    I guess that most who ever saw nearby pyroclastic flows saw them last.

    Pele is not like that - more oozy and less gassy. Italy's Etna and Guatemala's Fuego have none of Pele's geniality.
     
  4. tochatihu

    tochatihu Senior Member

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    This recent friskiness has retired ~350 homes in 35 days, repaving ~20 km2

    From 1983 to 2016, 4,4 km2 and 215 homes. Slower, but with better aim.
     
  5. tochatihu

    tochatihu Senior Member

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    For 1.5 months this has dominated global earthquakes above magnitude 2.5 threshold. Lack of large earthquakes is beginning to seem odd. Maybe. Earth being so large, it is hard to suppose that pressure release in one place could cause quietness far away.

    Mag 7 earthquakes are 10 to 20 per year, recent lack of these may mean nothing...
     
  6. tochatihu

    tochatihu Senior Member

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    Know what's weird? Not clear-mechanism weird, just maybe-it's-a-coincidence weird.

    From 2012 through 2017, global earthquakes of magnitude 6 or more averaged 11.7 per month.
    From Jan through Apr 2018, global earthquakes of magnitude 6 or more averaged 9 per month.

    Since May 3 when current Kilauea activity began, there have been 2.7 per month. Not counting a 6.9 at Kilauea.

    I don't know that this current 44-day fewness is particularly unusual; deeper digging required.

    Action site in Kilauea has had 50 to 500 earthquakes per day, but those have been much smaller. Rest of world, 20 to 30 per day above mag 2.5.

    Earthquakes in general occur when local strain overcomes frictional forces between rock-chunks in disagreement. No evidence that a magma leak far away can influence those battles.

    I'm go in' with coincidence for now. But it does sort a stick out.
     
  7. bisco

    bisco cookie crumbler

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  8. fuzzy1

    fuzzy1 Senior Member

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    For the statistics experts out there, just how unlikely or uncommon is this quake shortage? Is it significant, or is this just humans grasping for patterns?