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    Re: Big Full Moon and Perigee Spring Tides
    From: Richard B. Langley
    Date: 2011 Mar 19, 13:02 -0300

    Hate to nitpick, but best not to call it the "Daiichi Problem." "Dai
    ichi" just means "number one" in Japanese. It is certainly not the
    West Coast's number one problem. Maybe the "nuts" are. ;-)
    -- Richard Langley
    On 19-Mar-11, at 10:57 AM, Apache Runner wrote:
    > Frank -
    > I'm at Cape Cod today, and we do have some big tides today, so that
    > much is interesting.
    > I did a bit of digging on the definition of high astronomical tide
    > and low astronomical tide.  There is a move to try to standardize
    > this for bathymetric datum for all charts, but a) the US is still
    > using MLLW (mean lower low water) and b) the definition of
    > astronomical tides is a bit elusive.
    > In an operational definition, it seems to be the 'lowest' tide
    > recorded over some longish time period.    A more thorough
    > definition in other countries seems to be based on the metonic cycle
    > of 19 years.    A even more thorough definition would be the earth
    > at perihelion, the moon at perigee, the sun and moon in conjunction
    > and both the sun and moon at zero declination, which my source tells
    > me will next happen in 6580 AD.    I don't think any country uses
    > this definition.
    > Regarding the west coast panic, my cousin who lives in San Francisco
    > e-mailed me, asking about potassium iodide tablets.    I resisted
    > the urge to reply "R U NUTS?", and instead composed a thoughtful
    > message with all the reasons why the Daiichi problem cannot affect
    > the US West Coast.
    > John H.
    > On Sat, Mar 19, 2011 at 5:20 AM, Frank Reed  > wrote:
    > An article from S&T about some of the exaggerated claims regarding
    > the Full Moon today:
    > http://www.skyandtelescope.com/observing/home/118265299.html
    > It makes a simple, excellent point: "When it comes to science
    > stories, if you don't know it in numbers, you don't know it at all".
    > There's also some good advice on "frantic aunts" forwarding brain-
    > dead emails.
    > -FER
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    > --
    > Keeping up with the grind
    | Richard B. Langley                            E-mail:
    lang@unb.ca         |
    | Geodetic Research Laboratory                  Web: http://www.unb.ca/GGE/
    | Dept. of Geodesy and Geomatics Engineering    Phone:    +1 506
    453-5142   |
    | University of New Brunswick                   Fax:      +1 506
    453-4943   |
    | Fredericton, N.B., Canada  E3B
    5A3                                        |
    |        Fredericton?  Where's that?  See: http://
    www.fredericton.ca/       |

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