Sayonara, Japan? The Aira Caldera

Update: I have followed this at my other blog with posts on predicting eruptions and on the published paper by the Kobe University volcanologists.

Image of Mount Fuji by Swolib.  Taupo image by NASA

Image of Mount Fuji by Swollib. Taupo image by NASA

Some stark headlines have come out recently, along the lines of “Major Volcanic Eruption Could Make Japan ‘Extinct,’ Study Warns.”

The fuss is over news of a study on Japanese volcanoes that’s due out on November 11.

Kobe University volcanologists Yoshiyuki Tatsumi and Keiko Suzuki-Kamata studied 120,000 years’ worth of eruptions at Aira caldera and other Japanese volcanoes. Some of these have been supereruptions. They discovered that the country faces a 1% risk of such an eruption in the next 100 years.

That doesn’t sound like much, but it’s exactly the same statistical risk that the city of Kobe faced for a major earthquake the day before a M6.9 earthquake happened there in 1995.
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Guest video: Iceland’s Laki Volcano 1783

Today, volcanic eruptions are spectator sports…whee!

The volume of lava poured out by Bardarbunga volcano’s ongoing eruption just surpassed that of all other effusive eruptions in Iceland since the eruption of Laki Volcano in 1783-1784. Bardarbunga is tiny in comparison to Laki, though.

It’s difficult for us to understand just how huge and how devastating that eruption was for Iceland and the rest of the world.

Fortunately, we aren’t facing the same risk today from Bardarbunga.

Here are two short videos the BBC posted from its Timewatch episode on Laki. Check out this source for more details on that eruption, too.


Guest Video: Preparedness Now, The Great California Shakeout

We took part in the Great ShakeOut here in Oregon this week. I didn’t do too well, so it was a terrific wake-up call. However, I was disappointed by the reaction of many people.

While scheduling some guest videos for you, in the unlikely event that my writing projects tie me up for part of next week, I came across this one, “Preparedness Now, The Great California ShakeOut.” It’s good enough to share today.

Remember, when the ground starts moving, duck, cover, and hold on! And as I learned this week, just thinking through your disaster plan doesn’t work too well – do a walk-through.

Guest video: USGS, “Volcano Hazards”

Time is a bit short this week, so today I am just sharing some USGS videos about volcanic hazards and Yellowstone volcano. (Be sure to check out the USGS website listing alert status of all US volcanoes.)

What’s that? Yellowstone?

Yes! Here is a three-part series of informative videos about the supervolcano by Jacob Lowenstern, scientist in charge at the Yellowstone Volcano Observatory.



The 10 Worst Natural and Man-Made Firestorms



Firestorm-made thermal column. Fire (1) makes hot air (2) to rise forming storm-winds (3) towards the fires. A = Pyrocumulonimbus. Source

Wildfires are dangerous, but firestorms are downright terrifying.

They happen when conditions are right for the soaring air column over fire to develop its own momentum (PDF). This makes ground winds turbulentand they pour into the center of the conflagration, increasing its heat and spreading it around.

The process becomes self-sustaining. In fact, it will continue to grow as long as there is fuel available.

Firestorms occur naturally. As well – and this is heartbreaking – human beings sometimes start them, accidentally or on purpose.

Be aware that we’re going to look at representative World War II firestorms here – Stalingrad, Hamburg, and Hiroshima – as well as the deadly but, somehow, more humane natural or accidental ones. (I have set the Hamburg video, filmed by a local fireman, to stop before it gets to the bodies.)

Here, then, in chronological order, are ten of the worst natural and man-made firestorms over the last one hundred years.
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Flood Control, Part 3: Dhaka, the UK, and Jackson, Mississippi

We’ve seen that the two chief methods of flood control involve building barriers and keeping river channels open so they can hold as much water as possible.

How does that work out in real life? Let’s see how real-life flood control has been handled for:

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Flood Control, Part 2: Channeling the River

In a flood people turn first to barriers – levees, sandbags, flood walls, and the like. This works well, but failure can be catastrophic.

In emergencies, a spillway will drain flood waters away from the most threatened areas.

For long-term control of riverine flooding, though, you must engineer the river channel, deepening it and preventing bank erosion, so it will hold more water.

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Flood Control, Part 1: Building Barriers

We saw last week how floods happen. Now let’s take a look at the major methods of flood control.

Barriers are the first thing people instinctively turn to when they see a flood, no matter what its size.

Tremble at my mighty foot, puny rain river!  Morguefile/hotblack

Tremble at my mighty foot, puny rain river! Morguefile/hotblack

For 5,000 years, we have been raising permanent or temporary barriers to manage areal, coastal, or riverine flooding that’s extensive enough to endanger homes, property, and lives.

And then there are those among us who stand on the seashore, looking out over the ocean and thinking, “What a waste of really good land…”

(Note: I don’t know who Ernest Kleinberg was, but this 30-minute 1950s or 1960s film is both informative and enjoyable to watch.)

Next week, we’ll look at how people manage rivers to control flooding. Then we’ll wrap up this three-part series with brief looks at how flooding is managed in Dhaka, Bangladesh; Jackson, Mississippi; and London, England.


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