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Japan Science

Mt. Fuji May Be Close To Erupting 269

SpuriousLogic points out an article at Wired discussing research into pressure levels inside Mt. Fuji's magma chamber, which scientists claim is higher than it was in 1707, the last time it erupted. "The new readings, taken by the National Research Institute for Earth Science and Disaster Prevention, reveal that the pressure is at 1.6 megapascals, nearly 16 times the 0.1 megapascals it takes to trigger an eruption." A series of earthquakes shook the area around Mt. Fuji a little over a decade ago, and a fault line was discovered underneath it. "Since the March 2011 tsunami and the 6.4 magnitude earthquake that followed four days later, Japan has been on tenterhooks, and in May 2012 a professor from Ryukyu University warned that a massive eruption within three years would be likely because of several major factors: steam and gases are being emitted from the crater, water eruptions are occurring nearby, massive holes emitting hot natural gases are appearing in the vicinity." While the rising pressure within the magma chamber is of concern, it is but one factor among many that lead to eruptions.
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Mt. Fuji May Be Close To Erupting

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  • by G3ckoG33k ( 647276 ) on Friday September 07, 2012 @01:28PM (#41262517)

    They have indeed had more than enough of natural disasters, as well as self-triggered disasters.

  • by ACK!! ( 10229 ) on Friday September 07, 2012 @01:28PM (#41262529) Journal
    From the article: "Regions that would be affected, including Kanagawa, Yamanashi and Shizuoka, plan to hold a test run of an evacuation by 2014, with a meeting of local governments covering progress of the plans and of shelter preparations slated for April 2013." It seems if the pressure is higher than the last time the damn mountain went boom that they would speed up preparations a tad. Wow, laid back disaster relief.
  • by RobertLTux ( 260313 ) <(gro.nitramecnerual) (ta) (trebor)> on Friday September 07, 2012 @01:38PM (#41262717)

    could they maybe drill a set of holes and
    1 steer the lava to someplace NOT populated
    2 prevent the lava camber from going full bore BOOM

    when using Po^HMnt Fuji for your scam always set your clock for Volcano Day

  • by Maximum Prophet ( 716608 ) on Friday September 07, 2012 @01:42PM (#41262783)
    I had a can of Mellow Yellow that didn't get a pull tab installed, so I kept it as an conversation piece. It got left on it's side for a few years, and the contents ate through the aluminum lid. I think the sides of the can were coated, but not the top. Most can machines keep their cans on the side, so they won't last more than a decade or so if not refridgerated.
  • by Anonymous Coward on Friday September 07, 2012 @01:56PM (#41263077)

    Having it expressed in units familiar to us Yanks is quite useful. Putting it in psi let me see right away that it's about 16 times atmospheric pressure (which I know to be ~14 psi, so x 16 = 224). Hmmmmm, 16x, 16x...where I have seen that number before? Oh, yea - in the summary, where it says, "16 times what it takes to trigger an eruption".

    So after seeing that, it's clear that all the article's breathlessly informative science tells us that what it takes to trigger an eruption is to have pressure inside the volcano is....wait for it....HIGHER THAN THE PRESSURE OUTSIDE. Wow. We couldn't have figured that one out ourselves.

    So, yes, the guy posting the Olde English units not only gave me a better understanding of the forces, it helped me understand the article was more than a little sensationalistic. Which to me is damn helpful.

  • Re:"Nearly"? (Score:5, Interesting)

    by gman003 ( 1693318 ) on Friday September 07, 2012 @03:15PM (#41264889)

    Probably more than you think.

    My high school had an Engineering Ethics class, mandatory for all students in a tech-related major. One of the case studies was the Pentium FDIV bug, and how Intel handled it. Other case studies included Tacoma Narrows, Chernobyl, and a bunch of other forgettable ones.

    I graduated HS in '09. So "my generation" may be learning about it in a history class rather than through usage, but we *are* learning about it.

    In other words, "no, YOU get off the lawn, old man!"

  • by Rei ( 128717 ) on Friday September 07, 2012 @04:20PM (#41266163) Homepage

    I find it funny to hear all of the worry about things like Fuji. I mean, I know, I get it, it's roughly 100 km from Tokyo, which is a huge super mega-city. But living here in Iceland, hearing other places talking about "active" areas just seems kind of funny. I mean, the ground in parts of the capital region here in Reykjavík is just several hundred years old. On the hill right next to where I work, they drilled a 90 meter pipe into the ground, put a choke on the top, drip in water, and it erupts regularly as a geyser. A quarter of the city's hot water comes right from downtown. I mean, half an hour's drive (plus a bit of a walk) from my house you can walk *inside* a magma chamber. Not a lava tube, the actual magma chamber. It's empty now but there's other active magma chambers in the region.

    And we're not considered one of the more active regions.

    Fuji erupts every few hundred years, the biggest being VEI 5? Yawn. Katla's been threatening to go off any day now for the past couple years, and she's a VEI 6. And she's got an ice cap on top; last time she had a big eruption, she sent down a flood with as high a flow rate as the average outflow of the Amazon, Mississippi, Nile, and Yangtzee combined. That is, as much water flowing by as would fill up a cube over 200 feet on each side (roughly equivalent to a city block of 20-story buildings), every second.

    Japan is volcanically active? As much as a third of the lava on Earth in the past 500 years is estimated to have come from Iceland.

    Fuji's last big eruption was in the early 1700s? In the late 1700s we had Laki go off, most devastating eruption in recorded human history. A fissure opened up 23 kilometers long, up to 200 meters wide in places, with lava fountains as much as 1.5 kilometer in the air, erupting for 8 months straight. Sulfur dioxide was equivalent to a Mt. Pinatubo every three days. But that wasn't the worst, the worst was the anomalously high amounts of hydrofluoric acid. The eruption killed 80% of Iceland's sheep and even directly caused 23,000 human poisoning fatalities in the UK from the deadly blood-red cloud, as well as bizarre weather including tremendous thunderstorms with hailstones large enough to kill cattle.

    So yeah, yeah, I know, Fuji is more of a threat because Japan has such huge coastal populations and economic activity and stuff, I fully understand that, but still... I guess your perception of risk is relative to your environment.

  • by Rei ( 128717 ) on Friday September 07, 2012 @07:52PM (#41268895) Homepage

    Slightly larger in terms of volume of ejected matter (20 km^3 vs. 14 km^3), but nowhere near as devastating. It's the gasses that are the problem, and while Krakatoa emitted 20 million tonnes of sulfur dioxide (considered a huge amount - by comparison, Mount St. Helens was only 1.5), Laki emitted a staggering 120 million tonnes. The really extreme example was hydrogen fluoride, which is normally a minor volcanic gas. At 8 million tonnes, Laki put out almost half as much HF as Krakatoa put out in *sulfur dioxide*. Really extreme, and really devastating.

  • by Sussurros ( 2457406 ) on Friday September 07, 2012 @08:28PM (#41269199)
    He's an Icelander and they're not like normal people. In 1973 a group of Icelanders stopped a lava flow from engulfing their town with hoses while any township in any other country would have admitted the futility of even trying and walked away to start new lives somewhere else.

    I'm personally quite familiar with living near active volcanoes, occasionally waking to find the city covered with one or two centimetres of volcanic ash - pretty but not fun. I've been able at times to look out of my relatives' windows to see a direct view of Mount Tongariro and its ever changing plume, and I've even spent time in places where people cook food by burying it and letting the natural heat of the ground do the cooking. But nowhere I've been or even heard about matches the Icelanders' strange relationship with their volcanoes.

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