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+--- Thread: Volcanic eruption preparation checklist (/showthread.php?tid=19420)
RE: Volcanic eruption preparation checklist - ironyak - 05-03-2018
I didn't run across Moore's 1983 paper on the explosive origins of the Pawai and Puulena craters on the south edge of Leilani Estates, but this Hazard Analysis from 1994 had some interesting summary info on ash events.
TLDR: The probability of explosive eruptions, caused by interaction with groundwater and creating ash, is low but not zero. For large scale events, the estimate is less than a 1% chance in a 50 year period, but may be as high as 8% - 19% in a 50 year period for small scale events (covering a few square miles) like those seen in the lower east rift zone.
https://pubs.usgs.gov/of/1994/0553/report.pdf
Only two tuff (consolidated ash) deposits (Moore, 1983, 1992; Moore and Trusdell, 1991) are exposed on the surface of the ERZ.A single unit of tuff surrounding Pu'ulena, Pawai, and Kahuwai craters on the LERZ was deposited by vigorous phreatic and phreatomagmatic eruptions between 1,270 and 490 years B.P. The tuff of Kapoho Crater was deposited between 340 and 200 years B.P. Both deposits covered areas of at least 4-6 km2. Deep well SOH-1 encountered 13 ash units in the top 748 m of the drillhole (Novak and Evans, 1991), and SOH-4 encountered 19 ash units (each less than 15 cm thick) in the 2001 m core hole (Trusdell et al., 1992) within the LERZ.
...
Phreatic or Phreatomagmatic eruptions: The probability of explosive eruptions is relatively low but is not zero. Two such eruptions occurred within the Kama'ili and Kapoho subzones; the earliest is between 490 and 1,270 years old. Based on this information, the probability of another such eruption within 50 years would be between 8% and 19%.
...
In any case, all available information suggests that the probability of a moderate to large ash-producing volcanic event is less than 1.0% within 50 years. The probability of a smaller ash-producing volcanic event might be as high as 8% to 19%.
RE: Volcanic eruption preparation checklist - AKpilot - 05-03-2018
We have acreage in Pa'auilo. Let us know
We're all here, because we're not all there!
RE: Volcanic eruption preparation checklist - terracore - 05-04-2018
Here's a quick anecdote to bump this topic.
I had an instructor who was out on a camping and rafting trip that started before St. Helens showed any sign of eruption. Of course it being 1980 there were no cell phones and they hadn't bothered to pack a radio. Also, the Cold War was in full swing with the USA and USSR with both their fingers on the ICBMs that would ensure mutual annihilation.
As they were rafting down a river the ash fallout began. They thought it was nuclear fallout. They thought WWIII was underway and humanity was finished. It took them a good day to get to the next beacon of civilization when they found out it was "only" a volcanic eruption.
Fortunately, we have Punaweb to keep us informed.