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Earth Japan Science

Killer Qualities of Japanese Fault Revealed 58

Posted by Soulskill
from the can't-blame-the-kaiju-anymore dept.
Lasrick sends this report from Nature News: "The devastating 2011 earthquake and tsunami in Japan shocked researchers who did not expect that the seismic fault involved could release so much energy. Now the world's deepest-drilling oceanographic ship has been able to pin down the odd geology that made this disaster so horrific. The fault turns out to be unusually thin and weak, the researchers report in Science this week1–3. The results will help to pin down whether other offshore faults around the world are capable of triggering the same scale of disaster. ... The coring revealed a very thin clay layer, about 5 meters thick, separating the two sliding tectonic plates (abstract). 'That’s just weird,' says Emily Brodsky of the University of California, Santa Cruz (UCSC), who is an author on all three Science papers this week. 'Usually it’s tens of meters or more.' Lab tests confirmed that this wet clay layer is extremely slippery, and gets even more so under stress (abstract). As sliding creates friction and heat, water in the clay gets pressurized and pushes up against the impermeable rock around it. That 'jacks open the fault” says Brodsky, allowing it to slip even more. The temperature sensors found that more than a year after the quake, the fault was still up to 0.31 C warmer than its surroundings (abstract). From this they could extrapolate how much heat was generated from friction during the sliding event. Their calculations confirmed the very low friction of the 5-meter-thick clay layer."
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Killer Qualities of Japanese Fault Revealed

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  • The first couple times I saw the title I thought it said "Killer Qualities of Japanese Fruit Revealed". Granted, that also could have been really interesting.
    • Thats why I think before choosing a font.
      "LModern Caps" for example, never let me down to be trolled like that.
    • by TeknoHog (164938)
      I just misread it as "Killer Qualities of Japanese" as in the Japanese people, those innate math/programming genii with black belts in all known martial arts, including bondage and bukkake.
  • by mysidia (191772) on Saturday December 07, 2013 @05:10PM (#45628743)

    Perhaps by drilling millions of holes; and driving millions of rods of steel rebar into the clay, to reinforce the fault line.

    • Uh, what? Plate tectonics can push Mt. Everest to 29000 feet, and we are going to fix it with concrete and rebar?

      • by mysidia (191772)

        Plate tectonics can push Mt. Everest to 29000 feet, and we are going to fix it with concrete and rebar?

        Plate tectonics can do that, but over hundreds of millions of years -- not overnight.

        The idea isn't to stop plate tectonics.... it's to delay the sliding a couple hundred years :)

        • by GNious (953874)

          Yeah, let's make it build up more pressure before release - that'll work juuuuust fine! :)

          Note: Please don't do this anywhere near where I live, go on vacation or work.

          • by mysidia (191772)

            Yeah, let's make it build up more pressure before release - that'll work juuuuust fine! :)

            In 100 years or so, there will probably be even better technology available to more effectively add friction to the fault line, or transfer the kinetic energy from the release, so the fault begins to form in some safer place.

            • by RockDoctor (15477)

              In 100 years or so, there will probably be even better technology available to more effectively add friction to the fault line, or transfer the kinetic energy from the release, so the fault begins to form in some safer place.

              Or it'll form in some less safe place. Or somewhere no better and no worse (but without the century-worth of investment.

              In fact, your scheme wouldn't work. The stress would just move up to the top (or bottom) of your re-bar reinforced layer and start slipping there. You'd have to chil

              • by mysidia (191772)

                And then the fault would start to develop either seawards or landwards of the section that you've locked. Big progress. Not.

                Sure... after thousands of years.

                What's next on your agenda for repairing? The steady brightening of the Sun due to accumulation of helium in the core?

                OK..... orbit massive translucent film around earth; completely enclosing upper atmosphere in "transitions" lenses sunglasses material, that darken as the sun brightens.

                • That would deal with the visible light. Which is not the problem : the problem is IR radiation.

                  Also, where are you going to get the gigatonnes of carbon for your film? Strip mine the organic matter of the planet which you are trying to keep habitable for organic beings?

                  I know that you're being facetious, but both schemes are similarly silly.

      • by gweihir (88907)

        Uh, what? Plate tectonics can push Mt. Everest to 29000 feet, and we are going to fix it with concrete and rebar?

        People have no concept of orders of magnitude anymore. This is a few 1000....000 times harder than the human race can manage.

    • by fred911 (83970)

      There's a joke here using the words "Fault Tolerant"... just slips me.

    • Japan seems to have made most of their buildings pretty earthquake safe already. Fixing the earth seems like a less efficient step even assuming we were sure we weren't going to make it worse. Japan regularly experiences and ignores earthquakes which would cause a lot of damage elsewhere.

      That's not to say we should discount any possibility of fixing the plates to suit us. California for example has been taking some cues from Japan in earthquake proofing, but hasn't done nearly as much, and will be fac
      • by Mashiki (184564)

        Don't forget that they also design their cities with firebreaks in mind, entire sections of cities are designed to stop fires from running wild throughout even with the collapse of buildings and NG ruptures. It's not fool proof but if you only lose 1/10 of a city to fire instead of the entire thing because you can't get emergency services rolling, or a lack of water it sure does help. Wish I could find the articles on it from a few years ago, very interesting, I'm pretty sure Natgo has also done a few sho

    • Sure, provide me with a few billions and I will the job.
      Worried about being scammed? I WILL guarantee no 9.0 Earthquakes along that fault for the next 100 years.

      I am so confident of my product that I will even throw in the 100_years/8.5 warranty if you buy now with your credit card!

    • Just get some Utah Boy Scout leaders [youtube.com] to give that fault a nice shove. It's all about saving lives!
    • by rubycodez (864176)

      most theoretical studies I've seen of artificially tampering with fault zones to make them safe have ways to constantly release pressure, rather than letting it build up.

      • As if we need another reason for Japan to keep its heavy water out of the ocean...
        • by rubycodez (864176)

          that's not a concern.

          heavy water is not even radioactive, in concentrations of thousandth or less it has no observable effects. the concentration in a plant or animal becomes high, several percent and up, it does start interfering with enzymes and cell division. but those studies that poison creatures had to use tens (not tenths) of percent

  • Most of the info is in the Nature article, the paper, though probably funded by the taxpayes, is securely behind the AAAS paywall. Maybe Congress, if it had any balls, would make it illegal to publish publically funded research behind a paywall, but I digress.

    The message here seems to be that there were really two geologic events on the subduction zone of Japan's northern coast in March 2011. The first was an an ordinary subduction quake at modest depth in the plane of the Benioff Zone, a thrust event, b

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