Mt. Fuji May Be Close To Erupting

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Mt. Fuji May Be Close To Erupting

Posted by Soulskill on Friday September 7, 2012 @05:21AM from the must-be-fukushima's-fault dept.

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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Another thing to worry about... by redbeardcanada · 2012-09-07 05:24 · Score: 5, Funny

I am going to Japan in October, so in addition to earthquakes, tsunamis, radiation, ninjas, and godzilla, I now also have to worry about lava??? Damn...
1. Re:Another thing to worry about... by camperdave · 2012-09-07 05:51 · Score: 3, Informative
  
  I am going to Japan in October, so in addition to earthquakes, tsunamis, radiation, ninjas, and godzilla, I now also have to worry about lava??? Damn...
  Don't forget vorpal bunnies
  Well, that was a waste of time. No vorpalness, no attacks, no fights, nothing at all but a bunch of rabbits scurrying after pellets.
  
  --
  When our name is on the back of your car, we're behind you all the way!
2. Re:Another thing to worry about... by Rei · 2012-09-07 08:20 · Score: 4, Interesting
  
  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.
  
  --
  Alanis, you oughta know: she's older than you, more mature than you, and can show some restraint in a theater
3. Re:Another thing to worry about... by shutdown+-p+now · 2012-09-07 09:48 · Score: 3, Funny
  
  Remember, you don't have to run faster than tentacled sea monster / battle mech. You only have to run faster than the guy next to you. And then you can turn around and watch - that's the looked forward to part.
4. Re:Another thing to worry about... by Rei · 2012-09-07 11:52 · Score: 3, Interesting
  
  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.
  
  --
  Alanis, you oughta know: she's older than you, more mature than you, and can show some restraint in a theater
5. Re:Another thing to worry about... by Sussurros · 2012-09-07 12:28 · Score: 3, Interesting
  
  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.
  
  --
  I said - don't look Ethel!..., but it was too late..., she'd already looked.
I feel sorry for the Japanese by G3ckoG33k · 2012-09-07 05:28 · Score: 3, Interesting

They have indeed had more than enough of natural disasters, as well as self-triggered disasters.
Evacuation test run next year ??? by ACK!! · 2012-09-07 05:28 · Score: 5, Interesting

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.

--
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1. Re:Evacuation test run next year ??? by chromas · 2012-09-07 06:58 · Score: 4, Funny
  
  They don't want to risk premature evacuation.
2. Re:Evacuation test run next year ??? by magarity · 2012-09-07 07:36 · Score: 5, Informative
  
  Its not like everyone can simply form an orderly line and proceed calmly to the nearest exit
  Apparently you've never been to Japan.
  See some of the pictures from the last earthquake and tsunami; people evacuating the subway stations are stopped and standing to one side in a neat line on the halted escalator to let emergency workers go down past.
Re:In Olde English units by meekg · 2012-09-07 05:33 · Score: 5, Informative

Pressure vessels get increasingly difficult to build as their size grows.
When a 150 PSI compressor tank goes (and they do, even though they are made out of steel, a lot thicker than a soda pop can) they take away the room with them.
This pressure vessel is probably miles on a side, and the walls don't have good tensile strength - it's just gravity that's holding it down.
In short converting it to Olde English units doesn't help.
Re:Better rescue the coke machine by Maximum+Prophet · 2012-09-07 05:42 · Score: 3, Interesting

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.

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Re:"Nearly"? by Anonymous Coward · 2012-09-07 05:43 · Score: 5, Funny

My P5 system says 1.6 / 0.1 = 16.000739068902037589.
Re:"Nearly"? by tippe · 2012-09-07 05:44 · Score: 3, Informative

In their defence, both 1.6 and 0.1 are likely numbers that are rounded from some more precise measurements. The term "nearly" probably applied to the original measurements as opposed to the nicely rounded numbers presented in TFA. Just sayin'...
Re:"Nearly"? by Calydor · 2012-09-07 05:47 · Score: 4, Insightful

I'm curious, do you say, "I'll be there in 58 minutes and 48 seconds," or do you say, "I'll be there in an hour?"
I'm pretty sure both the .1 and the 1.6 megapascals is a rough estimate and not a 100% exact, set-in-stone figure.

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Re:Drill a hole, relieve the pressure? by oogoliegoogolie · 2012-09-07 05:59 · Score: 3, Insightful

IANAV, but I would guess that a 30cm bore hole wouldn't have much of an effect on a magma chamber that is miles wide.
Re:What triggers an eruption? by hawguy · 2012-09-07 06:01 · Score: 3, Insightful

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
If that's what it takes to trigger an eruption, why didn't it happen 1.5 megapascals ago?
Probably the same reason why even though a cigarette is enough to trigger a gasoline explosion, people still manage to smoke while fueling their cars without blowing themselves up - a cigarette is sufficient to set it off, but it takes a combination of factors to make it happen.
Re:Drill a hole, relieve the pressure? by RabidReindeer · 2012-09-07 06:18 · Score: 5, Funny

They want to, but Bruce Willis already died in space saving the world from that asteroid.
So who inherits his iTunes collection?
Re:Better rescue the coke machine by TheRedSeven · 2012-09-07 06:21 · Score: 5, Informative

True. Most metal cans (the kind used for packaging, anyway) are coated with a layer of plastic to prevent interaction with the Al/Sn in the metal of the substrate itself. Particularly with acidic contents (tomatoes are the ones that come most readily to mind.) Can *ends* are manufactured separately and joined to the can bodies themselves after filling. Some can ends are coated with plastic over the majority of the surface, but others have perforations and other 'gaps' that allow for proper sealing/seaming between the can and the can end, and for tabs to break through, etc. Any place the plastic coating is missing and an acidic ingredient can come into contact with the metal, corrosion can occur (though slowly).

Source: I'm a market researcher specializing in food/beverage packaging in the US.
Re:"Nearly"? by flyingfsck · 2012-09-07 06:31 · Score: 4, Insightful

I wonder how many people here are old enough to get your joke?

--
Excuse me, but please get off my Pennisetum Clandestinum, eh!
Re:how do they know by ppanon · 2012-09-07 06:41 · Score: 4, Insightful

They probably figured it out based on the pattern and quantity of ejecta. i.e. to launch boulder of this size this distance and to cover this area with this much ash then, assuming the lava reservoir was roughly the same size as it, the pressure needed to be X.

--
Laissez lire, et laissez danser; ces deux amusements ne feront jamais de mal au monde. - Voltaire
Re:"Nearly"? by gman003 · 2012-09-07 07:15 · Score: 4, Interesting

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!"
Re:"Nearly"? by YttriumOxide · 2012-09-07 19:11 · Score: 3, Funny

I wonder how many people here are old enough to get your joke?
At work about 6 months back, I heard a colleague humming "Daisy"; and joined in with the words:
Daisy, Daisy, give me your answer do,
Getting hazy, can't divide 3 by 2,
My answers I cannoy get 'em,
They are stuck in my Pentium,
I could be fleet, my answers sweet,
With a workable FPU.
What was truly awesome however was that another work colleague joined in about half-way through.

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