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    Re: New Moon, Perigee, and Solstice
    From: Rodney Myrvaagnes
    Date: 2003 Dec 23, 11:31 -0500

    On Mon, 22 Dec 2003 21:02:22 +0000, Trevor J. Kenchington wrote:
    >Which I think is the same as your explanation albeit in different words.
    >However, the Manual continues:
    >"It is possible that this phenomenon [meaning the greater lag of the
    >solar tides, not the Age of the Tide directly] is due to dissipation of
    >energy in the coastal fringes."
    >Which approaches my supposed explanation, without being quite the same.
    >However, the Manual is over 60 years old now and there must have been a
    >lot of relevant research in that time. Can you suggest somewhere I could
    >go for a fuller account of the cause(s) of the Age of the Tide?
    You can't separate these things as causes. Someone earlier referred to
    the "Q" of electrical tank (RLC) circuits. The oceans as confined by
    the bottom, continental shelves, and edges have some equivalent circuit
    consisting of myriad tank circuits connected in various serial/parallel
    combinations. Friction (R) in places like the Dover Strait lower the Q
    of the system as a whole.
    A plain example of "C" would be Minas Basin, while the lower part of
    Fundy is largely "L," in that the inertia of the flows dominate the
    friction against the sides. The English Channel is a lot of L as well.
    To say that such an equivalent circuit exists is a very long way from
    being able to write it down. However, local pieces of the circuit, such
    as the Bay of Fundy, may be quite well understood.
    For example, it is apparently known well enough to say that adding some
    R at the top of the Bay, by putting a tide mill there, would tune the
    bay toward resonance, rather than away. Hence the phrase "Canada's
    answer to acid rain," referring to the Maine real estate that would be
    lost to a higher tide line.
    I am sorry I can't give you numerical weights for these different
    contributions, but I hope this gives at least a qualitative
    Rodney Myrvaagnes                                                              
                          Opinionated old geezer
     "It is, of course, quite true that no great amount of skill is required to 
    navigate a ship most of the time, and
    on those less frequent occasions when a higher level of competence is 
    desirable luck may suffice. If that runs out there is always insurance..." 
    __The late Captain Richard Cahill

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