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GPS Could Speed Tsunami Warning 82

Posted by ScuttleMonkey from the early-warning dept.
wwood_98 writes to tell us that Wired is running a story about how GPS could serve more than its traditional role. From the article: "International organizations like the Pacific Tsunami Warning Center, or PTWC, in Hawaii currently depend on coastal seismic stations to record deep-sea earthquakes that could cause giant waves. But according to Jeff Freymueller, a geophysicist at the University of Alaska Fairbanks, data from GPS receivers could provide quicker, more accurate estimates of the magnitude of a tsunami-causing quake, buying time for evacuation. Freymueller presented his findings at this week's American Geophysical Union conference in San Francisco."
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GPS Could Speed Tsunami Warning More

GPS Could Speed Tsunami Warning

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  • GPS buys you a head start! (Score:4, Funny)

    by mister_llah ( 891540 ) on Monday December 19, 2005 @10:37PM (#14296142) Homepage Journal
    Excellent, if you live in a coastal city, you'll get to know that you have 20 minutes left to live...

    • Re:GPS buys you a head start! (Score:5, Informative)

      by Mr. Flibble ( 12943 ) on Monday December 19, 2005 @10:44PM (#14296175) Homepage
      Excellent, if you live in a coastal city, you'll get to know that you have 20 minutes left to live...

      According to the SAS Survival manual by John Weisman - if a Tsunami is inbound your best defense is to be over 1km inland or 100ft above sea level.

      In many (not all) places you would have time to do either of these. You also have the option of quickly heading out to sea as the Tsunami only has effects at shallow depths (right by the coastline). So, an additional 20 min could indeed save a huge number of lives.

      I would also add, that you might not be safe even 1km inland if you were withing a natural "funnel" like a trianglar river delta with highlands on each side...
      • Those are fairly good rules of thumb, but if I know a tsunami is inbound, I would take "best defense", and accept "modest defense" as better than "no defense". :-)

        In last year's tsunami, often people that sought shelter on the third floor survived. Those that stayed in one-floor shelters were washed away.

        The densest population areas (coastal India) that happen to be the most vulnerable are the ones least able to use this information. In general, there aren't any buildings to seek shelter in, and the lan

    • Excellent, if you live in a coastal city, you'll get to know that you have 20 minutes left to live...

      You misspelled the last word. You have 20 minutes left to drive. Inland. As quickly as your car can. You should be okay about 20-30 miles from the coastline.
      • You can try and drive out in your car.

        You'll be going nowhere, because everyone else will be trying to go, too.
        My motorcycle will make much better time.

        You'll be fine!
        • i bicycle should get you to safety, or hell even your feet if you can walk/RUN FOR YOUR LIFE at 6 miles per hour sustained for 2 miles you will be ok or at least less likely to die than in the area directly hit by the wave
      • Word of impending doom spreads like wildfire... people would find out relatively quickly, I think everyone simultaneously trying to leave an area at the same time might cause a lot of problems actualling leaving...

        So you'd wind up drowning in your car...

        ===

        However, there is always the chance you could be one of those first few to make it out... you never know!
        • At least if traffic is like Atlanta where I live, you would die among friends
          Actually, IIRC, Ney Yorkers suffer similar traffic but are much less benevolent. Too bad, they are a hell of a lot more likely to get hit by a tsunami than Atlanta.

      • Re:GPS buys you a head start! (Score:5, Funny)

        by martinX ( 672498 ) on Monday December 19, 2005 @11:36PM (#14296366)

        No, you have 20 minutes to:

        • get dressed (pants at least),
        • find the keys,
        • grab your wallet,
        • look for your cell phone,
        • turn off the TV,
        • grab the backups you always make,
        • where is that cell phone?,
        • select a playlist for your iPod,
        • grab some cold brewskies
        • where is that damned cellphone???,
        • don't forget the digital camera

        THEN you can drive. If you're not busy blogging the event, telling the other blogophiles you'll be AFK for a while.

    • More than enough time for them to lie down or put paper bags over their heads.
  • I don't see what GPS receivers can do here that accelerometers can't.
    • err... what are you talking about? GPS reports back your location, in latitude/longitude/altitude. Accelerometers read back your rate of acceleration. Sure you could find location with an accelerometer, but it would be relative... not absolute like GPS.
      • Absolute location is not necessary in order to determine the amplitude of an earthquake wave (you already know the latitude and longitude of the station, of course).

        Highpass filter at perhaps .001Hz to eliminate drift, integrate twice, and you've got the amplitude of any earth motion.
      • I can envision an underseas quake that does
        *not* cause a ripple on the oceans surface.

        So, there are situations that may fail to
        give an accurate early warning.

        At the same time, this does sound like a worthy project.

        • Re:Accelerometers (Score:1, Informative)

          by Anonymous Coward
          Without ripple on the oceans surface you don't have a Tsunami. Just a Submarine earthquake.

    • RTFA (Score:2)

      by joggle ( 594025 )
      Seismometers are essentially very high precision accelerometers in that they record the local acceleration of the ground. The GPS receivers provide a total change in position caused by an earthquake which helps the tsunami models be more accurate.

      Another way GPS receivers can be used is by placing one on a buoy a few miles off of the coast. When a tsunami passes the buoy, there will be an unusually long-period wave detected by the software monitoring the buoy's position. When this occures shortly after an

  • Cool stuff (Score:3, Informative)

    by Sen.NullProcPntr ( 855073 ) on Monday December 19, 2005 @10:42PM (#14296163)
    I was assuming this would only work if the quake happened under dry land. From The Fine Article;
    "GPS receivers measure the static displacement of the earth, and after the first few minutes of a quake, that doesn't change much."

    But looks like there may be a way to detect a tsunami caused by an under sea event;

    "Quakes that cause tsunamis create deformation on the surface of the water, and that causes an atmospheric 'thump,'" MacDoran said. "A compression wave travels into the upper atmosphere, and that disturbance causes subtle changes in the way GPS signals travel." Digital processing of the changed signals coming from nearby receivers would indicate that a tsunami was imminent.

    Sounds promising but is it possible to tell the difference between air movement caused by a tsunami and just a sudden gust of wind? How dense would the sensor array need to be to prevent false positives?

    • It sounds to me like they're saying that this "thump" would subtly affect radio propagation in the ionosphere, which isn't subject to weather.

      /didn't read the article, as it's not good Slashdot form to do so.
      • /didn't read the article, as it's not good Slashdot form to do so.

        It's okay to read the article after you post. Just be sure not to read it before you post, especially if you know nothing of the subject.

  • Grade of GPS being used? (Score:3, Interesting)

    by Funakoshi ( 925826 ) on Monday December 19, 2005 @10:43PM (#14296165)
    Does anyone have any further information regarding what grade of GPS is being used? Based on the price point, I would have to guess that it is Mapping grade GPS equipment, but the problem would be that in order for Mapping grade GPS to update, the person (or mount) holding it, must be moving to get the corrections from the satellite. Survey grade may work, but it wouldn't be under $10k per receiver.

    Any help?
  • for GPS devices on the ground, I doubt they'll do much good for earthquakes that happen deep on the ocean floor; and those seem to be the ones that generate the most powerful tsunami.

    Still, cheaply covering part of the risk is definitely worth it.
    • Actually, the GPS units on the ground are used to feed into the seismic streams so that a more accurate assessment of the earthquake can be made. If the seismic instruments tell you 8.0, but a GPS receiver 300km away moved by a certain amount, you can be certain that the location or size is wrong. If you have an accurate deformation field 100's of km away, you can assess the results of the seismic instruments quickly. There is a big difference between an 8.0 and a 9.0 EQ.

      Check out SCIGN (Southern California

  • Traditionally, the AGU meets in San Francisco in the early part of December, in between the end of classes at the Universities and the start of the Holiday rush.

  • GPS COULD be used on volcanos? (Score:3, Informative)

    by dsci ( 658278 ) on Monday December 19, 2005 @10:59PM (#14296254) Homepage
    From TFA:

    "With GPS, the displacements are measured second by second," said Bock, who also presented at the American Geophysical Union conference. "Within 70 seconds you have a good idea of the final deformation." In addition to predicting tsunamis, he thinks GPS modules could be used to monitor the activity of volcanoes and landslides in real time. [emphasis mine]

    I thought GPS was already used extensively in volcano studies.

    http://vulcan.wr.usgs.gov/Monitoring/GPS/framework .html [usgs.gov]

    No specific mention of real time data whacking in that link? A quick Google, and we find this, for example:

    http://www.gmat.unsw.edu.au/snap/publications/jans sen_etal2002c.pdf [unsw.edu.au]
    • GPS is used extensively at Volcanos. In fact, some of my software is used to download the GPS receivers at the Hawaiin Volcano Observatory. However, real time assessment of the deformation is not used as much. Luckily, A volcano is a fairly small area and real time kinematic (RTK) GPS [wikipedia.org] can be used with accurate results. The only requirement is a static GPS site installed outside the area of the deformation zone.

      RTK is not a useful in an earthquake region since it requires a site to remain stable and for the

  • Worthwhile - $181 per person in 2004 (Score:5, Informative)

    by Kamiza Ikioi ( 893310 ) on Monday December 19, 2005 @11:01PM (#14296260)
    The article is interesting in the use of GPS recievers to gather information. Let's look at two datasets.

    From Wikipedia [wikipedia.org]: "The accuracy of the GPS signal itself is about 5 meters (16 ft) as of 2005 and has steadily improved over the last 15 years. Using differential GPS and other error-correcting techniques, the accuracy can be improved to about 1 cm (.4 in) over short distances."

    From NASA [nasa.gov]: "Large earthquakes often cause permanent movement of the Earth's surface, a result of the motion that occurs deep underground. The tsunamis spawned by the magnitude 9.0 earthquake on December 26, 2004, were the result of motions of the sea floor above the earthquake fault. Seismic measurements and computer models show that the Burma Plate slipped up to 20 meters (66 feet) at the location of the earthquake, 18 kilometers underground. The sea floor above moved less, up to 5 meters (16 feet) vertically and 11 meters (36 feet) horizontally."

    So, the practical uses of this, even without error-correction, are theoretically viable for creating an early warning system for Tsunamis.

    The article states that it should only really take 70 seconds for "a good idea of the final deformation". Linking this data to website and government run servers, the early warning system for Tsunamis would be far greater and accurate that say, tornado early warning systems. Consider the following exerpt from PBS's NewsHour: Developing a Global Tsunami Warning System [pbs.org]: "STUART WEINSTEIN, Geophysicist, Pacific Tsunami Warning Center: I think the 'holy cow' moment didn't occur until we started getting the first preliminary reports over the wire services that, in fact, a damaging wave struck Phuket, Thailand and Sri Lanka.

    BETTY ANN BOWSER: Were you frustrated?

    Stuart WeinsteinSTUART WEINSTEIN: Very frustrated. Frustrated and to a certain extent humiliated. It's humiliating for me as a geophysicist working for a tsunami-warning program to learn first of a tsunami from a wire service than from a tide gauge. That -- it doesn't get any worse than that, quite frankly.

    BETTY ANN BOWSER: Thousands of miles away at NOAA's Pacific Marine Research Lab in Seattle, tsunami researcher Vasily Titov was also frustrated. It took him until 4 a.m. in the morning of the next day to run this computer model, because he didn't have tsunami readings either."

    Considering the earthquake hit at 00:59 GMT, and the wave first makes landfall at Sumatra 01:30 GMT, then 02:30 GMT in Thailand, then 03:00GMT in Sri Lanka and India... having a result from this system at 01:00GMT (70 seconds) automatically piped to the national emergency centers of governments, could have at least mobilized aid faster in Sumatra, and could have evacuated thousands in Thailand, Sri Lanka, and India.

    A total of approximately 275,000 died in the Indian Ocean Tsunami of 2004. At a cost of even $10,000 per detector, 5000 detectors for $50million USD would have only cost $181 for every person that died.
  • You would think that projects like this, with such potentially positive results for every country with a coastline, would be a real focal point for government spending. Unfortunately, it seems like too many governments only find money for these things after the fact, when TV screens start showing the after-effects of catastrophes. As much as I believe that a global early warning network is a good idea, I am pessimistic about it ever being completely implemented, for reasons of bureaucracy and cost.



    Neve [neverendingbillboard.com]

  • Article text in case of /.'ing (Score:1, Informative)

    by Anonymous Coward
    (and posting as AC, so I'm not karma whoring, Jeebus)

    GPS Could Speed Tsunami Warnings

    By Elizabeth Svoboda

    GPS satellite receivers are already navigational must-haves for hikers and drivers. Now scientists are hatching plans to press them into service as tsunami predictors.

    International organizations like the Pacific Tsunami Warning Center, or PTWC, in Hawaii currently depend on coastal seismic stations to record deep-sea earthquakes that could cause giant waves. But according to Jeff Freymueller, a geophysic

  • Might work for a little while (Score:3, Funny)

    by commodoresloat ( 172735 ) on Monday December 19, 2005 @11:34PM (#14296357)
    Until the tsunamis get ahold of these [qsl.net].

  • A better use for GPS? (Score:3, Interesting)

    by thisjustin ( 878053 ) on Monday December 19, 2005 @11:41PM (#14296385)
    I think this article (and the researcher) missed the point of a far more profound, yet more far-off, use of GPS in earthquake detection. Spectrum recently ran a story describing how the GPS system among other things could sense impending earthquakes days, weeks, and even months in advance of an earthquake. The basic concept is the cracking of rocks in the crust leading up to an earthquake frees electrons which rush downward creating positvely charged holes. These holes also appear at Earth's surface and attract electons out of the ionosphere. The phase difference of the two signals the GPS satelites transmit is affected by this change and the change from normal values can be detected. This is still a long way off, and the use of GPS to measure this phenomena is only one and definitely not the best. But it sounds better than the couple hours mentioned in the article.
  • Just wanted to add that these GPS measurement stations put up for this purpose could give valauable information that could also be used for other many purposes, I can mostly think of geophysics purposes as that is what I work with myself, but I imagine such a web could be used for many other things

    I remember a paper about the isostatic rebound [uwgb.edu]after the icecap in Scandinavia where GPS recievers were used [anu.edu.au]. A curiosity I remember from the paper was that at the coastal areas there were quite a lot more unce

  • But (Score:4, Interesting)

    by Catmeat ( 20653 ) <mtm&sys,uea,ac,uk> on Tuesday December 20, 2005 @07:35AM (#14297600)
    More accurate seismometers would be nice. But one thing about sea-floor earthequakes is that some generate tsunamis and some do not. That's why NOAA spends a bucket-load of money maintaining a network of deep-ocean pressure sensors on the bed of the Pacific (link [noaa.gov]) These work because a tsunami in deep ocean has a wavelength vastly greater than the depth of water so it produces a small, but characteristic and detectable, pressure pulse as it passes over the sensor.

    If this GPS idea works as advertised, it'll be a very useful incremental improvment to the tsunami warning networks. But it'll hardly be revolutionary. Being able to determine which events will produce a tsunami just from the seismic data - that would be revolutionary.

  • Freymueller presented his findings at this week's American Geophysical Union conference in San Francisco

    That's funny ... I thought it was two weeks ago [agu.org].

  • Sirens and evacuation routes are such a 20th century way of warning people about tsunamis. How often does a car alarm go off that you automatically tune out?

    It would seem like a better idea to have a sort of public-safety warning system integrated with the mobile phone network. This way, the authorities could simply send SMS messages (or even graphic messages) to people within a specific geographical area, giving them the nature of the incident in question.

    I think we had something like this that put m

  • about how they would use GPSr's to measure *seafloor* movement. Is this thing submerged and anchored to the floor of the ocean? Or is it a buoy with an umbilical to something fixxed to the seafloor? Or is it a buoy that simply floats and measures at the surface only?

    I'm sure they have considered it, but I don't see it in the article.
  • They should be using Inertial Navigation Systems [knowprose.com]. And Wired should fix it's registration process.

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