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Thread: Kīlauea Activity

  1. #91
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    Given what "we" know about the structure and eruptive history of Kilauea, there's a very good chance that magma will return to the caldera and Halemaʻumaʻu crater. At some point the dynamics or cycles that drive the rift eruptions will shift, stopping the flow of magma into the fissures. Even with the crater filling in with the various summit collapses, that part of the volcano represents a "weak" area that the repressurized magma can move back into and begin the process again. It might be worth it to look up the histories (native and European) of Kilauea to get a sense of how "normal" this event is, and how often magma has retreated and returned to the summit.

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  2. #92
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    Quote Originally Posted by Selfsim View Post
    What I'd like to know, (if answerable), is whether the now mostly devoid of magma, Halemaʻumaʻu caldera, can ever refill once again?

    If the magma 'streams' from the fissures can solidify all the way from the coastal outfalls back to the fissure(s), then can the fissure(s), themselves, also seal over and force the fluid magma to well up all the way back to the main caldera? I guess if the subsurface magma reservoir outflows and pressures ever subside enough for the ocean outfalls to solidify again, then the caldera could again refill .. however, this would now seem unlikely, and fissure 8 may end up being be Pele's new residence .. (or maybe her retirement home?)

    And what about Puʻu ʻŌʻō? I think its level has dropped during this event as well. What's going to happen there?
    Quote Originally Posted by Trebuchet View Post
    "Ever" is a really long time. I'd think it might not take that long at all. The current east rift zone event is nothing new -- similar events have occurred many times, including the Kapoho eruption of 1960. The eruption map also shows flows right in this area from 1955. Eventually the underground plumbing will clog, or the lava supply will be reduced, and this event will come to an end. I'd guess (and IANAG) this will probably happen before the end of this year. Activity will then return (eventually) to the summit and/or Pu'u O'o.
    And here's a USGS page about a similar collapse/explosive event in 1924. And the top "geology and history" page showing almost the entire surface of the east corner of the island to be less than 1000 years old. It's cyclical, and will continue to be for a long time.
    Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

  3. #93
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    Quote Originally Posted by Trebuchet View Post
    And here's a USGS page about a similar collapse/explosive event in 1924. And the top "geology and history" page showing almost the entire surface of the east corner of the island to be less than 1000 years old. It's cyclical, and will continue to be for a long time.
    Ya .. thanks. And thanks to CJSF, too. Much appreciated.
    I was reading up on that last night and watching some documentaries on the history of it all.
    I suppose if its all so regular/predictable and rather 'business as usual' then one has to wonder why they allowed building major housing estates in the already known rift zones .. more a rhetorical question here .. (and posed numerous times here also I notice) .. but is also one posed frequently in the documentaries.

    Anyway, if the caldera level continues to drop (due to fissure 8 discharge) then it seems it may enter the explosive phase again. (This is apparently expected 'imminently' in geological times).
    Is anyone measuring the magma levels in the caldera? I've seen the satellite photos, but I haven't found any 'dipstick' measurements online. (Perhaps the 'dipper' fried whilst doing their job and they need a replacement? )
    I guess they rely on the summit (and flank) deformation data for that, but it indicates more the shift in subterrranian magma, rather than the actual depth in the caldera (the latter of which is the key measurement for predicting a sustained explosive phase?)

  4. #94
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    Quote Originally Posted by Selfsim View Post
    ... then one has to wonder why they allowed building major housing estates in the already known rift zones .. more a rhetorical question here .. (and posed numerous times here also I notice) .. but is also one posed frequently in the documentaries.
    Yup. Private property rights are held rather sacred in the USA. That doesn't mean insurance companies have to issue policies, of course. In my part of the world, people keep building houses in flood plains, and worse, like the lahar zone of Orting, WA. It's not a question of IF Orting will be covered by feet of steaming mud, just when.
    Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

  5. #95
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    Though of course if people only lived somewhere geologically stable, with no danger of flood, hurricane, tsunami, or tornado, it would start severely limiting where humans could live. Which is not to say I'd move to Orting.
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  6. #96
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    Indeed. One of these days the Cascadia Subduction Zone is going to slip.
    Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

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