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Science

Oceanic Sounds of Last Year's Earthquake 75

Posted by Zonk from the science-on-a-massive-scale dept.
DoctorBit writes "Columbia University's Lamont-Doherty Earth Observatory is reporting that some of their researchers have analyzed recordings of the underwater sound produced by last year's magnitude 9.3 Sumatra earthquake. By studying the ocean's sound waves rather than the Earth's seismic waves, the researchers measured the earthquake's speed and duration with unprecedented accuracy."
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Oceanic Sounds of Last Year's Earthquake More

Oceanic Sounds of Last Year's Earthquake

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  • probably (Score:1, Funny)

    by truckaxle ( 883149 )
    sounded like a very large gaint fart.... Riiiiiiiiiiipppppp.

  • Sustained energy (Score:5, Informative)

    by TimTheFoolMan ( 656432 ) on Saturday July 23, 2005 @07:15PM (#13146666) Homepage Journal
    What's interesting in listening to the MP3 is the sense of sustained energy over such a long period of time. Surreal...

    Tim

    • Chili... (Score:5, Funny)

      by Saeed al-Sahaf ( 665390 ) on Saturday July 23, 2005 @07:28PM (#13146724) Homepage
      What's interesting in listening to the MP3 is the sense of sustained energy over such a long period of time. Surreal...

      Amazingly, this is the sign of good chili as well.

    • Not really surprising (Score:5, Interesting)

      by Derling Whirvish ( 636322 ) on Saturday July 23, 2005 @07:57PM (#13146846) Journal
      It's not really surprising at all. A lightning bolt makes a distinct short crack if you are close to it, which becomes the sustained rumble of thunder if you are much distance away. In fact, the length of the rumble increases as the distance between you and the lightning bolt increases. It's due to the reflection of the sound off other objects spreading the sound out. The same phenomenon should happen with the sound of an earthquake as it travels through the earth's crust should it not? Because the sound was recorded some distance away, it should not equal the same length of time the "earth's crust was ripping" anymore than the sound of thunder some distance away from a thunderstorm is a record of the duration of the earth's atmosphere ripping from a lightning strike.
      • thunder sustain is produced primarily via reflection, diffusion, and refraction through thermal layers of the atmosphere and the ground. As well, assuming the strike was close to the ground, the initial impulse of a lightning strike is enough to buckle the ground, creating a secondary impulse travelling upwards like a dome of sound: milliseconds behind the primary reflection the above will occur on a large expanse of flat land adding terrain, vegetation, manmade structures etc, will significantly alter t

      • Re:Not really surprising (Score:1, Insightful)

        by Anonymous Coward
        That's not the case here. The great earthquake of 2004 ripped apart the crust of the Earth for approximately 150 km [usgs.gov]. The fact of the matter is that if all of that energy were concentrated at one point, and released simultaneously, it would have left a crater (the energy of the quake was larger than if all of the world's nuclear weapons were detonated).

        It is also unreasonable to believe that 150 km of crust would be rigid in the sense that all points snapped simultaenously. In reality what occured is tha
        • ya I realize quakes are not instantaneous detonations, however any confined-spectra wavelet cloning that occurs in the uncompressed audio file would account for SOME of the sustain....I have no idea how much, and from the sonographic shots of the seafloor after the quake, it's glaringly evident this was a monsterous cascaded release of energy

    • Don't hear anything... (Score:3, Interesting)

      by antdude ( 79039 )
      Maybe it is these cheap headphones, but does this MP3 require a subwoofer (I'm at work so...) to hear as well? I hear nothing even though Winamp shows audio movements in its visualizer.
    • I have my headphones on listeing to this, and I agree that it's surreal. I mean, just being able to hear the raw power present is simply stunning.

  • Detecting Submarines (Score:4, Insightful)

    by reporter ( 666905 ) on Saturday July 23, 2005 @07:16PM (#13146668) Homepage
    The phrase "unprecedented accuracy" seems to imply that this technique can detect very minute underwater sounds. Would this technology also be applicable to detecting the barely detectable sounds of underwater nuclear submarines?
    • You sir will be contacted shortly by the NSA with regards to your views about blowing up barely detectable underwater submarines.

    • Re:Detecting Submarines (Score:1, Interesting)

      by Anonymous Coward
      Probably not.

      I haven't RTFA, but at a guess they're taking what they use to listen to nuclear submarines and using that to listen to the Sumatran earthquake.
    • It would be my opinion that this is technology was created by the military, and then adapted by science. Which is one of the pro's of war, it spurs technological advances. The applications of this technology could be huge, especially in dealing with earthquakes, which of the majority happen under water.

    • Re:Detecting Submarines (Score:4, Informative)

      by iamlucky13 ( 795185 ) on Saturday July 23, 2005 @08:04PM (#13146873)
      No, it would not. As the article says, the sensors were in place to help ensure adherence to the nuclear test treaties by detecting nuclear detonations, which are a heck of a lot louder than nuclear submarines (it has been said that the Ohio class SSBN's are quieter than the ocean around them...currents, fish, etc).

      There does, however, already exist several large sonar chains known as SOSUS [wikipedia.org] (SOund SUrveillance System). These were built by the navy in the 50's specifically for tracking submarines. It was upgraded over the years, but since the need has dwindled, it is not actively manned anymore. If I remember correctly, recordings from this were used to help the Russians figure out what went wrong on the Kursk.

      • Re:Detecting Submarines (Score:4, Informative)

        by demachina ( 71715 ) on Saturday July 23, 2005 @09:14PM (#13147100)
        I think SOSUS is manned, but by reservists, its slowly fading away not because the mission has dwindled, but because its obsolete.

        Its been supplanted by IUSS(Integrated Undersea Surveillance System) [fas.org] which is monitored by regular Navy personel.

        Lockheed has a $100-150 million dollar contract for Phase II IUSS which I think is coming online any time now.

        There are still plenty of submarine threats in the world and the U.S. isn't going to stop tracking them anytime soon.
        • SOSUS is not manned by reservists, and is alive and well. There are several station around the world. IUSS is the integration of SOSUS and the T-AGOS programs. The T-AGOS ships are what tow towed arrays around the ocean and look in areas where SOSUS can't see. Although you might not see it, the SOSUS program isn't shrinking, it is expanding to cover new areas.
          • I had read in a news article during one of the noteworthy accidents, although I don't remember for certain which one but I think it was the Kursk, that sounds of the accident had been recorded by SOSUS but not noticed immediately because the stations were no longer manned full time. While I'm not surprised that the system is being expanded, it also seems logical that there would be less need to monitor, for example, the GIUK gap as closely as during the cold war.

            I would be interested in finding out more
    • This array would likely be able to do it's share in submarine tracking, but only as piece of a larger system.

      Part of the adventure of sonar detection is that low frequencies, especially the 30-100Hz range, travel thousands of miles with very little loss. This trick to long range submarine detection is listening for sounds from pumps, fans, etc, in those low ranges. Next, you need a wide baseline to triangulate a position. The SOSUS arrays covering the Greenland-Iceland-Britan gap covered hundreds of m
    • If it said "unprecedented sensitivity", I'd be with you. But it doesn't. the sentence talks of the unprecedented accuracy of determination of location and speed of motion, etc. It doesn't necessarily mean that quieter sounds than before were heard, merely that they were correlated better.

      For other discussions of the difference between sensitivity and accuracy (resolution), see any of the discussions about whether or not we should keep the Hubble space telescope.

  • In case of Slashdotting (Score:5, Informative)

    by Anonymous Coward on Saturday July 23, 2005 @07:23PM (#13146701)
    The MP3:
    http://www.ldeo.columbia.edu.nyud.net:8090/news/20 05/images/tsun_eq.mp3 [nyud.net]

    The Article:
    http://www.ldeo.columbia.edu.nyud.net:8090/news/20 05/07_20_05.htm [nyud.net]

    Enjoy.
  • The question I guess is - is it as accessible as current detecting and measuring techniques. Yes it is more accurate - but it doesn't help if it costs 10 times as much - academic research grants are hard to come by if they don't generate profic.. even if it means saving lives.

  • caterpillar drive? (Score:5, Funny)

    by E8086 ( 698978 ) on Saturday July 23, 2005 @07:29PM (#13146728)
    Have I got this straight, Jonesy? A $40 million computer tells you you're chasing an earthquake, but you don't believe, and you come up with this on your own?

  • Yes, THAT earthquake (Score:1, Interesting)

    by Anonymous Coward
    For those "in the know" asking the same question as I did: Yes, it is about that earthquake that was predicted by Sollog [slashdot.org].

  • Faaaast! (Score:1, Insightful)

    by Anonymous Coward
    The first phase encompassed the first three minutes of the eight-minute earthquake, during which the rupture proceeded north at about 1.7 miles per second (2.8 km/sec) from the epicenter. During the second phase, the rupture slowed to 1.3 miles per second (2.1 km/sec) and continued north for another five minutes until it reached a plate boundary where the fault changes from subduction to strike-slip, where the two plates push past one another in opposite directions.

    For the astronomically challenged (my co

  • 192kbps (Score:1, Insightful)

    by E8086 ( 698978 )
    What are the chances the downloadable music industry can learn from this?
    This freely downloadable mp3 is encoded at 192kbps, 50% higher than most if not all tracks available from the legal music download companies, which we pay for.
    Now go and give the Red Cross some money for their continuing relief efforts.

    • Re:192kbps (Score:2, Insightful)

      by DrHanser ( 845654 )

      Of course it would have been better if it was recorded as a VBR recording. Let's also not forget that bit for bit, AAC is arguably better than MP3.

      Not all formats are created equal; bitrate is a pisspoor measure of audio quality. This is also not music, this is a sound -- there is a huge difference when encoding audio.

  • It is obvious to any idiot that the earthquake was caused by an imperial destroyer passing overhead. Damn their tractor beams.
  • well ...
    Lets just say for my comment's sake that these studies on speed and duration of the earthquakes could lead to new technologies to detect earthquekes earlier. That would be super nice, right?
    Wrong!
    All this earlier prediction has no use if the coastal cities that are prone to have earthquakes do not have emergency measures like alarms on the beach, "tsunami" drills with rescue teams, or even instructions on hotels and schools in how to behave in emergencies like that.
    Just in case we dont remem
    • All this earlier prediction has no use if the coastal cities that are prone to have earthquakes do not have emergency measures like alarms on the beach

      Alarm systems are fine for saving some people, but a large number of the deaths would still not have been prevented even if the people had known the tsunami was about to strike hours in advance.

      Homes were flattened, and much of the infrastructure was destroyed. Millions suddenly became homeless and there was little aid available for them. The only water ma

  • the audio anomoly immediately preceeding the quake (Score:5, Funny)

    by bobdotorg ( 598873 ) on Saturday July 23, 2005 @08:26PM (#13146955)
    the audio anomoly immediately preceeding the quake was the sound of the pulling of a tectonic finger.

  • You've gotta try this! (Score:4, Funny)

    by l0ungeb0y ( 442022 ) on Saturday July 23, 2005 @09:09PM (#13147081) Homepage Journal
    Man.... I cranked that bad boy up to 12db on my AV Reciever -- and it was like totally awesome man! Like everything started rumbling and shaking and it was like being in an earthquake or something man! And you like close your eyes and you're like there man! Yeah! It was like IMAX® but without being able to see anything. Far out!

    • Yeah my computer desk was vibrating nicely and the floor eve was slightly with only a crappy 10 watt sub! I'm going to have to play it on my 15" subs tomorrow hehe ;)
  • is this the quietest, most boring underwater earthquake ever recorded?

    • Subwoofer! (Score:3, Interesting)

      by antdude ( 79039 )
      Listen to speakers with a subwoofer. I had the same problem. I couldn't hear anything with headphones at work. I am at home now, and I listened to it again with my old Klipsch ProMedia v2-400. Wow. Nice bass!! It's all about bass with this audio clip.
      • Seriously, if any of you out there are working on some low-budget space movie or anything, this is the perfect accompaniment track for that huge spaceship you've got taking off/flying by. Layer it up with a couple of other tracks and you'll have a very nice full ship sound.
  • If this is the only way to measure it so accurately, how do they know it's so damned accurate? Wouldn't you have to test it against something else to know how your accuracy is, and if you could do that, why not just use the other method, if it's so accurate?

    /me is confused
  • ...as if thousands of voices cried out in terror...

    What, too soon?
    /ducks

  • Duuuuuuuude... (Score:4, Funny)

    by utexaspunk ( 527541 ) on Sunday July 24, 2005 @01:08AM (#13148008)
    Maybe I need to lay off the doobage, but if you play it backwards, I swear it says "BSD is Dead"
  • i remember back when i was in high school, i would think, what happens to sound. u know it gets softer, but does it really disappear?

    if it does, why does it disappear? what does it become? took me awhile to figure out that sound was a form of energy and it was probably converted into heat.

    but it's interesting to see that the underwater sound waves are still traveling from that earthquake. how long will it continue to travel? when will it finally disappear?
  • where is my 200W sub woofer when I need one !

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