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An Early Warning System For Earthquakes

Posted by kdawson on from the whole-lotta-shakin' dept.

Iphtashu Fitz writes "Would 15 seconds be enough warning time to prepare for an earthquake? It certainly wouldn't be long enough to evacuate from where you live, but it may be just long enough to get out of a building or brace yourself in a doorframe or under a solid desk. Italian scientists may have discovered a way to measure the initial shockwave of an earthquake two seconds after it starts, and from it predict the extent of the destructive secondary wave that will follow. It typically takes twenty seconds for the secondary wave to spread 40 miles, so sensors that can transmit warnings at the speed of light may provide just enough warning before a major quake for people to brace themselves. Even more importantly, such a warning could allow for utilities like gas companies to close safety valves, preventing potential fires or explosions in the aftermath of the quake."

14 of 147 comments (clear)

  1. One powerful earthquake? by solafide · · Score: 4, Interesting
    It takes 20 seconds for it to travel 40 miles? How much power has that secondary wave lost in those 40 miles? Wouldn't it take one really powerful earthquake for you to need to take cover 40 miles from the epicenter?

    (I'm not an expert on earthquakes, but 40 miles seems like a long way for the earthquake to travel.)

    1. Re:One powerful earthquake? by Harmonious+Botch · · Score: 3, Informative

      "Wouldn't it take one really powerful earthquake for you to need to take cover 40 miles from the epicenter?"

      Yes.
      Our house is about 20 miles from epicenter of the 1994 Northridge quake, the most costly quake ever recorded ( California housing is expensive ), and it was not damaged at all. I don't recall Oakland or Berkeley suffering much from the SF earthquake in the 90s, and they are less than 40 miles away.

    2. Re:One powerful earthquake? by Beryllium+Sphere(tm) · · Score: 5, Interesting

      1985, Mexico City, buildings collapsed when the center of the earthquake was 400 km away. That one was unusual but it shows what's possible.

      The other thing you can do with 10-20 seconds of warning is apply emergency brakes on the bullet trains, which I believe Japan has arranged to do.

    3. Re:One powerful earthquake? by Harmonious+Botch · · Score: 3, Insightful

      "1985, Mexico City, buildings collapsed when the center of the earthquake was 400 km away. That one was unusual but it shows what's possible."

      No, it shows what Mexican building codes are like.

    4. Re:One powerful earthquake? by sfjoe · · Score: 5, Informative


      The collapsed Cyprus freeway was in Oakland. It's believed that earthquake waves travel horizontally through the crust and can also be reflected off of harder layers further down. If the original wave and the reflected wave harmonize they can be extremely destructive even many miles from the epicenter.

      --
      It's simple: I demand prosecution for torture.
    5. Re:One powerful earthquake? by brian1078 · · Score: 4, Informative

      The epicenter of the 1989 Loma Prieta earthquake was in the Santa Cruz mountains, about 60 miles south of San Francisco and Oakland. Some of the worst damage was in these areas. The "Cypress Structure" of the I-880 freeway collapsed, as did a portion of the Bay Bridge. In the town, another 20 miles north of Oakland, I lived in at the time there was considerable damage to some older structures as well as to personal property.

      I would have been happy to have the 15 seconds notice.

    6. Re:One powerful earthquake? by davidsyes · · Score: 3, Interesting

      I was lucky that day. I had only minutes before left Grand View (Chinese) Restaurant (they changed names to Fortune after the quake) with a few cartons of food and couldn't decide whether to go straight back to Milpitas or to dart over to Embarcadero and shoot a few pictures.

      By the time I'd decided it wouldn't be good to get the food late to some people I told about the restaurant, when I decided to head on south, I was barely out of Oakland, somewhere south of Cypress on 880 because. Had I gone to SF, I'd have been SOMEwhere on the Cypress. It's possible I could have also been somewhere before the fallen deck section, but that all could have depended on how many people on the Cypress would have been in my way (back then I might have wanted to speed, might have just relaxed and slipped in and cranked up my Depeche Mode cassettes, (but instead I kept the KGO talk on), blah blah blah...) and I am SURE I'd have probably died that day had I not just taken the food straight to my friend.

      I think I was barely north of the Marina shopping outlet when my steering started acting up. I couldn't believe my barely 1 year old car was acting up. Then the radio went out. There wasn't too much traffic in that section, so my eyes fixated partly on the road and partly on the trees. When I saw them swaying, I knew my car was OK, but the radio was hissing. Only a few weeks earlier IIRC, KGO's antenna near the Dumbarton Bridge went out and needed repairs, so I thought they were having problems. I tuned to other stations only to hear noise and mostly silence, but sporadic bits mentioned major earthquake.

      Fortunately, the roads don't open up like they do in hollywierd flicks. Fortunately it wasn't in the thick of commuter traffic, or there might have been collisions all up and down the freeway for dozens of miles if anyone freaked and lost control of the car. I was fortunate that day...

      --
      Previously: "Linux... Toward the Sunrise..." Now: "Linux... Toward the-- No, now, part of Every Sunrise"
  2. Safety valves? by EaglemanBSA · · Score: 4, Interesting

    There would still be gas in the main lines, how would shutting a safety valve keep a broken pipe from leaking gas already in it?

    --
    Quiz: True or False -- On a scale of 1 to 10, what is your middle name?
    1. Re:Safety valves? by frosty_tsm · · Score: 3, Informative

      Possibly it would prevent the continued flow of gas to the pipe. Some would still leak, but either the gas would burn out quickly or dissipate before it's ignited.

  3. Huh? by Anonymous Coward · · Score: 5, Funny

    What do earthquakes need to be warned early about?

  4. Sigh by geekoid · · Score: 5, Informative

    "... brace yourself in a doorframe ..."

    this is a myth. The only thing this acomplishes is broken fingers.

    It stems from an observation from a red cross worker after a earthquake in mexico.(I think 1950ish.)
    That archtecture of the entrance way was an adobe arch. Arches are very strong, as opposed wooden square door frames.

    --
    The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    1. Re:Sigh by Beryllium+Sphere(tm) · · Score: 4, Informative

      There's still a door swinging in it. Depending on which way you're facing, you could get your fingers pinched in the hinges and mangled, or slammed into by a closing door and mangled.

      Drop, cover, and hold is what the Red Cross is teaching, after considerable research.

      First-world building are unlikely to collapse but you don't want to be hit by falling chunks of ceiling. Get under something like a table ("drop and cover") that will intercept some debris before it hits you.

      The table will likely start walking across the room as everything moves up and down and sideways. Keep a grip on a leg of the table or whatever and "hold" so that it doesn't walk away from you.

      Doesn't have to be a table, and improvising is good. At the grocery store you could use a shopping cart, for example.

  5. Doesn't japan have something like this? by Hays · · Score: 3, Interesting

    I thought the high speed trains in Japan would stop in the event of an earthquake (before the earthquake actually hit them), http://en.wikipedia.org/wiki/Shinkansen

    "In the event of an earthquake, an earthquake detection system can bring the train to a stop very quickly"

    Anyway, the idea of a broadcast system to warn of an earthquake is pretty obvious, the engineering task of doing it right without false positives is pretty difficult I bet.

  6. Re:Not enough time by Pyromage · · Score: 3, Insightful

    Of course more time would be better. However, nearly everything important can be done in 15 seconds. The really critical things. Like getting the generators at the hospital up to keep the ICU running. Closing gas mains. Taking the scapel out of the guys brain during surgery.

    You can't drive home from the grocery store and strap yourself into bed in 15 seconds, but you can do a lot of really really important things in that time.