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  1. #11
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    Default Re: The University of Oxford Has Created Conditions That Generate Freak Waves

    Flying into Edinburgh, you get a very close view of the sea and shore line. There is along sea wall at Port Seaton / Cockenzie and when the wind is in the NW it is a lee shore. The wave pattern of the reflected and refracted waves is very obvious and what surprised me was the distance back upwind and outwards that was disturbed by the reflected and refracted waves. I estimate that it was at least 3 miles. The wave construct / destruct wave pattern was very noticeable compared to the linear waves blowing down to the wall from the Kirkcaldy side. The water was also much darker suggesting a rougher sea state.
    "'...contradictions .... are deliberate exercises in doublethink." Orwell from 1984

  2. #12
    Join Date
    Nov 2001
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    Me: Johannesburg South Africa Yacht: Richards Bay East Coast Africa
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    Default Re: The University of Oxford Has Created Conditions That Generate Freak Waves

    We know all about freak waves down our way

    https://magicseaweed.com/news/how-th...ca-work/10997/
    Life is too short not to have a sea view
    Distantshaws tinyurl.com/yclt6l68

  3. #13
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    Jun 2013
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    Hopefully somewhere warm
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    8,782

    Default Re: The University of Oxford Has Created Conditions That Generate Freak Waves

    There might well be many colossal waves out there not caused by that mechanism as well though. Similar non linear rogue waves are known to occur in fibre optics.


    http://www.ercmultiwave.eu/images/pu...9April2012.pdf

  4. #14
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    Apr 2013
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    Default Re: The University of Oxford Has Created Conditions That Generate Freak Waves

    Thanks. Leaving aside the maths which is beyond me, is this particular mechanism in essence like oblique/partial clapotis but with independent wave trains meeting at 120 degrees, rather than a wave train meeting its reflection and forming a standing wave?

    (I have so far just skimmed the paper, and not checked if the 120 degree angle of train incidence is a real point of maximum interaction or just the largest angle they investigated, such that yet bigger effects might be found at even larger angles.)

  5. #15
    Join Date
    Nov 2015
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    190

    Default Re: The University of Oxford Has Created Conditions That Generate Freak Waves

    Quote Originally Posted by GHA View Post
    There might well be many colossal waves out there not caused by that mechanism as well though. Similar non linear rogue waves are known to occur in fibre optics.


    http://www.ercmultiwave.eu/images/pu...9April2012.pdf
    Pleased to see Tom Lehrer cropping up briefly there too... "Pollution", I think, though it's not named.

  6. #16
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    Nov 2018
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    Newport IoW
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    483

    Default Re: The University of Oxford Has Created Conditions That Generate Freak Waves

    Mustn't it be true that, for every big freak wave there must be a corresponding freakishly small wave?

    I've always understood it that freak waves are inevitable, given at least two superimposed wave trains which interfere with each other. Sometimes the crests occur in the same place at the same time, so doubling the height.
    Sometimes a trough must meet a crest, resulting in a calm spot.
    Very interesting film though.
    Ignorance killed the cat. Curiosity was framed.

  7. #17
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    Jun 2011
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    Berkshire, UK
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    Default Re: The University of Oxford Has Created Conditions That Generate Freak Waves

    Quote Originally Posted by Ladybirdgaffcutter View Post
    Mustn't it be true that, for every big freak wave there must be a corresponding freakishly small wave?
    A bell (shaped) curve of height distributions will no doubt have rarity slopes at both extremes. But not strictly symmetrical...

    Mike.

  8. #18
    Join Date
    Jun 2005
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    20,921

    Default Re: The University of Oxford Has Created Conditions That Generate Freak Waves

    The last time I saw something relating to freak waves it was suggested that Schrodinger's wave equation provided a mathematical model for waves in the sea. I've studied quantum physics so understand the wave equation but the Oxford work doesn't seem to mention it. one link here: https://folk.uio.no/karstent/waves/index_en.html
    If I'd wanted to live in a Banana Republic I'd have gone to South America.

  9. #19
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    Aug 2013
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    Default Re: The University of Oxford Has Created Conditions That Generate Freak Waves

    Quote Originally Posted by Ladybirdgaffcutter View Post
    Mustn't it be true that, for every big freak wave there must be a corresponding freakishly small wave?.
    I think what they are interested is not just the freakishly big - which is simple statistics - but the freakishly big and breaking. Normally waves only break when they smell the bottom - wave speed increases as the water gets deeper, so when a wave gets to water of a similar depth to its own amplitude, the crest travels faster than the trough and the wave breaks.

    Something which breaks without that is interesting because it means another mechanism is at work.
    "Seamen are always wanting to do things the proper way; and I like to do them my way."

  10. #20
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    Aug 2013
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    SW Scotland
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    Default Re: The University of Oxford Has Created Conditions That Generate Freak Waves

    Quote Originally Posted by savageseadog View Post
    The last time I saw something relating to freak waves it was suggested that Schrodinger's wave equation provided a mathematical model for waves in the sea. I've studied quantum physics so understand the wave equation but the Oxford work doesn't seem to mention it.
    It seems a bit far-fetched (ha-ha). Schrödingers wave equation describes the probability density of a single particle being somewhere, not the possibility of a super-large particle appearing from nowhere. I suspect that someone has seen "probability" and "waves" together and jumped to a conclusion.

    Mind you, it would save a lot in canal fees if we could tunnel from Ardrishaig to Crinan ...
    "Seamen are always wanting to do things the proper way; and I like to do them my way."

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