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Submarine Cables Could be Repurposed as Earthquake Detectors (economist.com)

Posted by msmash on from the how-about-that dept.

In a paper published in Science, Giuseppe Marra, of Britain's National Physical Laboratory (NPL), proposes to shine a little light into the oceans by co-opting infrastructure built for an entirely different purpose. From a report: Dr Marra and his colleagues hope to use the planet's 1m-kilometre network of undersea fibre-optic cables, which carry the internet from continent to continent (see map), as a giant submarine sensor. Dr Marra is particularly interested in earthquakes. The dry bits of the planet are well-stocked with seismographs. The oceans are much less well covered, with only a handful of permanent sensors on the sea floor. This means that many small earthquakes go unrecorded because the vibrations they cause are too mild to be picked up by distant land-based sensors. The genesis of the idea is a good example of the way in which advances in one field of science can lead to new developments in other, apparently unrelated fields.

26 comments

  1. I have an earthquake detector by Anonymous Coward · · Score: 0

    yeah, my DAMN balls, if they shake, u better quake

  2. They could also be used to detect temp changes by Anonymous Coward · · Score: 1

    This is an implementation of Rayleigh Scattering technology, which has been around awhile and used for FO sensing of movement and/or temp changes. It has limitations, such as difficulty in determining exactly where the earthquake took place along the line, unless you do a lot of calibration which would require actually disturbing the lines to verify.

    1. Re:They could also be used to detect temp changes by Anonymous Coward · · Score: 0

      why would you post this anon
      are you that chinese dude who stole our navy submarine or what

    2. Re:They could also be used to detect temp changes by Anonymous Coward · · Score: 0

      Wouldn't the wide-scale installation of these measurement systems also enable the detection of unauthorized traffic duplicator installations?

    3. Re: They could also be used to detect temp changes by Anonymous Coward · · Score: 0

      One of the authors here (see my comment elsewhere). We don't use redirections because telecoms fibres use one way amplifiers that would kill the signal. We use round trip interferometry on two fibres in the same cable.

      Never been done before. Plus, no one thought it could work on this scale.

      A

    4. Re:They could also be used to detect temp changes by mikael · · Score: 1

      It used to be possible to detect where a fault in an copper or fibre-optic cable through the use of time-domain reflectometry. Any defect would reflect some signal back, and the intensity/time could be correlated.

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  3. "1m-kilometre" by Rick+Schumann · · Score: 2, Insightful

    Wow, that's asking quite a bit of 39 inches of fiber optic cable.

    1. Re:"1m-kilometre" by Anonymous Coward · · Score: 0

      I had to read that twice as well. "million kilometer" or "billion meter" are easier to read; "vast" is adequate but not accurate; "large enough to circle the world 25 times" gives a more useful idea of scale than the actual number.

    2. Re:"1m-kilometre" by Anonymous Coward · · Score: 0

      I read that as 1 million km

    3. Re:"1m-kilometre" by Anonymous Coward · · Score: 0

      Even mega-kilometer would have been less confusing, or gigameter.

    4. Re:"1m-kilometre" by Anonymous Coward · · Score: 0

      i see as was One meter-kilometre and wonder this dumb shit is talking about.

    5. Re:"1m-kilometre" by Anonymous Coward · · Score: 0

      Sounds like about 1,000 m^2.

  4. Re:Trump could be repurposed as a propaganda effor by Anonymous Coward · · Score: 0

    I'd much rather see Donald J. Trump 'repurposed' as mulch.

  5. So in other words use an OTDR as a seismograph by pecosdave · · Score: 1

    I don't see why it wouldn't work. I guess they just didn't want to bust out the Optical Time Domain Reflectrometer nomenclature.

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    1. Re:So in other words use an OTDR as a seismograph by Obfuscant · · Score: 1
      Nobody doesn't understand why this wouldn't work, which is why the idea is several years old and is being actively used for land-based seismic sensors already, and if not being used has been floated as a use for dark fiber for long distances. There is no significant difference between undersea and on-land use of fiber in this context.

      My first response to this article is that Science has become subject to the same error of "dups" that /. has.

    2. Re:So in other words use an OTDR as a seismograph by Anonymous Coward · · Score: 1

      Nobody doesn't understand why this wouldn't work

      Jesus fuck man, I don't understand what you didn't not say .. because you didn't not don't say it well enough to allow me to doesn't not have any fucking idea what you did say.

      Sure as fuck lived up to your nickname there.

    3. Re:So in other words use an OTDR as a seismograph by Anonymous Coward · · Score: 0

      I guess they just didn't want to bust out the Optical Time Domain Reflectrometer nomenclature.

      I would assume they don't, because the article says they send the signal full loop and use interference, which can be far more sensitivities than an OTDR. They aren't even looking at reflections!

    4. Re: So in other words use an OTDR as a seismograph by Anonymous Coward · · Score: 0

      One of the authors here (long time /. lurker, never created an account). We don't use reflections because long distance telecoms fibres use isolators and one way amplifiers. Round trip interferometry using two fibres on the same cable is a nice little hack that circumvents this.

      So, no, this has never been done before :-)

      A

    5. Re:So in other words use an OTDR as a seismograph by Anonymous Coward · · Score: 0

      We "discovered" this effect on a metro dark fiber network at the old job a decade ago. There was mystery loss on a particular lnk. Someone noticed it was worse on windy days. Digging up the local weather data we found a correlation with strong northly winds. Somewhere in that path we had a fiber flapping in the breeze.

    6. Re: So in other words use an OTDR as a seismograph by pecosdave · · Score: 1

      I've done lots of LAN/SAN fiber, and even some SDI over single-mode, but I've never done telecom fiber. I've always wanted to dig into what's going on with the long-range backbone stuff.

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    7. Re:So in other words use an OTDR as a seismograph by pecosdave · · Score: 1

      Using fiber as a high-tech weather rock. I like it.

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  6. They can also be used ... by CaptainDork · · Score: 2

    ... as stationary hydrophones to listen for ships above and beneath the surface.

    Each vessel produces its own signature of vibrations caused by reefers, engines, screws, power source hum ...

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  7. Re:Trump could be repurposed as a propaganda effor by Anonymous Coward · · Score: 0

    Well the ground of the Federal Supermax will be happy to accept the nutrients regardless of the garbage being that they composed.

  8. Finally by Anonymous Coward · · Score: 0

    We will be able to pinpoint the exact location of CmdrTaco

  9. Re: They could also be used to detect temp change by Anonymous Coward · · Score: 0

    Typo: redirections = reflections