Oceanic Sounds of Last Year's Earthquake

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."

Comments

probably

[truckaxle]

sounded like a very large gaint fart.... Riiiiiiiiiiipppppp.

Wow!

[Anonymous Coward]

A tornado underwater! How weird.

Sustained energy

[TimTheFoolMan]

What's interesting in listening to the MP3 is the sense of sustained energy over such a long period of time. Surreal...

Tim

Re:Sustained energy

[Hinokagutsuchi]

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

[reporter]

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?

Re:Detecting Submarines

[pickyouupatnine]

You sir will be contacted shortly by the NSA with regards to your views about blowing up barely detectable underwater submarines.

Re:Detecting Submarines

[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.

Re:Detecting Submarines

[JonN]

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

[Anonymous Coward]

"Which is one of the pro's of war, it spurs technological advances."

Yeah, I can't wait for my Microwave Gun so I can finally fry all those damned ants in the front yard... my magnifying glass is too small. :)

Re:Detecting Submarines

[iamlucky13]

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 (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

[demachina]

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) 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.

Re:Detecting Submarines

[Anonymous Coward]

NSA? I think you mean FBI, CIA, or the DoD.

Re:Detecting Submarines

[Anonymous Coward]

As someone who "witnessed" the kursk incident first hand, I can say with some degree of certainty that sosus nets are still in operation, all over the world in fact. They are used primarily as a deterent nowadays though.

Science does piggy-back on the exsisting sosus nets as well.

Re:Detecting Submarines

[Neferkara]

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.

Re:Detecting Submarines

[iamlucky13]

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 about their status, but unfortunately, the FAS SOSUS entry has not been updated recently. It did mention, however, several stations, including Keflavik, Iceland had been closed.

In case of Slashdotting

[Anonymous Coward]

The MP3:
http://www.ldeo.columbia.edu.nyud.net:8090/news/20 05/images/tsun_eq.mp3

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

Enjoy.

Unprecendented accuracy...

[pickyouupatnine]

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.

Chili...

[Saeed al-Sahaf]

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.

Re:Chili...

[Anonymous Coward]

Gee, all the worlds problems would be solved if the vast majority of people were geophysicists!

caterpillar drive?

[E8086]

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?

Re:caterpillar drive?

[giantsfan89]

For the confused, the quote came from The Hunt for Red October.

Yes, THAT earthquake

[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.

Faaaast!

[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 condolences) that would make 9.07417417e-14 and 6.80563063e-14 Parsec/s, respectively

Re:This is really cool

[Fjornir]

'more realistic' ?

Please elaborate.

192kbps

[E8086]

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

[DrHanser]

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.

Re:192kbps

[Anonymous Coward]

yeah a 128kbps AAC (which i was i use on my ipod) sounds like a 192kbps MP3

Benefit of hindsight...

[Anonymous Coward]

20/20 vision with hindsight... what a surprise. There is so much pressure on academics to produce 'results' (i.e, something that makes the newspapers) that there is massive pressure on researchers to 'fiddle' the results to suit their purposes.

(Posting as AC because my UID gives away my position at CU)

Not really surprising

[Derling Whirvish]

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.

Re:Not really surprising

[Placebo Messiah]

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 the characteristics of thunder, but are not responsible for the general sustain. The same thing occurs underwater, but with a lot more efficiency

Re:Not really surprising

[Anonymous Coward]

That's not the case here. The great earthquake of 2004 ripped apart the crust of the Earth for approximately 150 km. 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 that it cascaded. One part of the crust slipped which provided the energy for the adjacent layer to slip. From physics we know that the rate of energy propagation due to shear stress is the speed of sound in that material (related to the bulk modulus for the material--which is why craters always form as hemispheres, but that is another story). So the fault kept of slipping at a very fast speed (but not instantly), over an enormous distance which is part of the reason why the sound file is so lengthy. One geophysicist remarked in another article (I think it was on MSNBC) that he could hear the crust being ripped apart. The frightening thing is that this was true.

Re:Not really surprising

[Placebo Messiah]

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...

[antdude]

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.

Re:Don't hear anything...

[Jimbookis]

Get rid of those tinny headphones and crank up the subwoofer. It's pretty impressive.

Re:Don't hear anything...

[antdude]

Jimbooki: I cannot have a subwoofer at work/cubicle. :(

Re:Don't hear anything...

[Anti_Climax]

You need a subwoofer to feel it but you don't need one to hear it.

I could hear it with my Sennheiser HD 280 Pros (and I could actually feel them shaking on my head), but hey, this MP3 is only one reason to get a set of Sennheisers. They're worth it.

Having listened to the sound ...

[ta ma de]

It is obvious to any idiot that the earthquake was caused by an imperial destroyer passing overhead. Damn their tractor beams.

what is the use?

[brunokummel]

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 remember "that" tsunami that hit sumatra were detected with more than one hour before it hit the coast and killed those people.

the audio anomoly immediately preceeding the quake

[bobdotorg]

the audio anomoly immediately preceeding the quake was the sound of the pulling of a tectonic finger.

Re:An international First Post

[Anonymous Coward]

Detta är den första kommentaren. Det finns andra kommentarer här, men denna var den första. Du kan påstå att andra kommentarer kom före den här, men du ljuger eftersom att detta är den första kommentaren. Med det sagt, var vänlig och moderera upp denna kommentaren. Tack så mycket.

Alarms are only the first step

[MarkByers]

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 many people could find was impure. People that were already ill had no hope of surviving and diseases spread with no medicine supply to stop them.

Installing some alarms and doing nothing else, will achieve very little. To save more, a lot more aid needs to be given from other countries in the days after the disaster.

You've gotta try this!

[l0ungeb0y]

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!

Re:You've gotta try this!

[sm00f]

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 ;)

Re:You've gotta try this!

[Deodat]

You "cranked it up" to just 12 dB, and it caused your house to shake? You know, you should probably consider getting your house's foundation retrofitted or something, or else it's gonna collapse as soon as you start saying anything...

Re:You've gotta try this!

[l0ungeb0y]

I live in a crappy little loft in downtown SF since I'm an indigent bastard who can't yet afford the million dollars for a home on my paltry 6 figure income you insensitive clod!

And I'm not sure if you're aware of just how low the frequencies are on that recording... or the effects of low frequencies on physical objects -- it makes them bump and funk and do the wild thang.

Re:You've gotta try this!

[Anonymous Coward]

I think the gp just doesn't know how the scale on AV receivers works - he's probably confusing db and db(A). While the latter gives an absolute measurment of sound pressure, the former usually doesn't. The "standard" would be to adjust an av receiver to produce 75db(A) at 0 db, so 12db would yield 87db(A). A lawn mower would be at about 85dbA, so 87dbA would be the noise level of two of those, which I don't usually run indoors, nor do those things produce freqeuncies as low as the average earthquake, so 12db does indeed shake the house quite a bit.

Sonar and Detecting Submarines

[AtomicSnarl]

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 miles.

Now comes the problem of sound ducting. The temperature and salinity gradients of seawater can steer sound in much the same way as a mirage is from bent light due to temperature gradients in the air.

The Fata Morgana mirage, also called Looming, is a prime example of a sonar problem. By eye, you see a mirror image of a distant, even over-the-horizon object reflected as if by a mirror -- the temperature inversion layer. By ear, you care only for the direction of the sound, but now the problem is "which mirror?" As the sound curves up to the sea surface, it reflects back down, then curves up once again, and reflects again, at about 33 mile intervals. This is called a Convergence Zone.

These complexities go on and on, and require a wide range of sensors by depth and distance to detect and resolve the location of a sound source. The computers come in handy to do the filtering ID work, so you don't mistake a squid or a beluga for a Typhoon or Krasnodar...

Is it my shitty laptop speakers, or...

[Junior J. Junior III]

is this the quietest, most boring underwater earthquake ever recorded?

Re:Is it my shitty laptop speakers, or...

[Anonymous Coward]

Except for the fact that it killed a quarter of a million people?

how do they tell?

[cryptoz]

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

Pompous asses

[Anonymous Coward]

Unfortunately, the vast majority of people are not geophysicists. I am.

I hope all geophysicists aren't pompous asses as well...

accuracy == sensitivity?

[YesIAmAScript]

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.

Holy Cow!

[Anonymous Coward]

I cannot have a subwoofer at work/cubicle

Jesus, what kind of sweat shop do you work in? They don't allow sub-woofers? Personally, I'd walk out.

Re:Holy Cow!

[antdude]

Where do you work? Let me work at your employer. :P

Morons

[blueadept1]

This is obviously whales farting.

Woohoo!

[root-my-box]

I now have one of the most kickass ringtones around! Thanks /.!

Subwoofer!

[antdude]

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.

Re:Subwoofer!

[justforaday]

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.

I sense a great disturbance in the Force...

[imnojezus]

...as if thousands of voices cried out in terror...

What, too soon?
/ducks

Yep, needs a subwoofer!

[antdude]

I just got home and just listened to it with my old Klipsch ProMedia v2-400. Wow. Nice bass!! It's all about bass with this audio clip.

Re:the audio anomoly immediately preceeding the qu

[SnapperHead]

http://www.freedesktopwallpapers.net/art/michelang elo-creation.jpg

And God saith unto Adam:
"Pull My Finger."

Duuuuuuuude...

[utexaspunk]

Maybe I need to lay off the doobage, but if you play it backwards, I swear it says "BSD is Dead"

i've always wondered what happens to sound

[krunk4ever]

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?

Re:i've always wondered what happens to sound

[Anonymous Coward]

Sound, which simply put is particles vibrating (moving back and forth). I'm sure you know how your ear works, with air pushing your eardrum back and forth, and this motion is translated into electric signals interpreted by your brain.

So yes, sound this disappear. It disappears because the energy of all these particles will be "absorbed" by the surrounding environment. Diluted so to speak, and also converted into other types of energy (such as heat, because there's friction between the air/water-particles).

Juts think of everything as energy. Nothing disappears, it just changes form (so yeah, you got it). So it goes from air, or in this case water, having kinetic energy, to something else. So in a energy kind of way, no, sound never disappears. But pragmatically, yes it does. Much like if you blow a puff of air with your breath, it will lose velocity fairly quickly. Same thing really.

If you've grasped what I've said so far, it's not a far stretch of the imagination to extrapolate this onto earthquakes etc. All the energy has to go somewhere, and some of it goes into collapsing buildings, creating tsunamis and what not. Also, this is the reason why there's no sound in space. There's no matter to displace to create "sound".

I hope this helped a bit...

That's the sound of...

[Anonymous Coward]

That's the sound of 262,000 people dying.

I figured even the Slashdot Crowd could take that seriously for once.

where is my ...

[dangil]

where is my 200W sub woofer when I need one !