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    Re: Navigating Around Hills and Dips in the Ocean
    From: George Istok
    Date: 2003 Aug 15, 23:12 -0500

    Mr. Huxtable,
    
    The gravitational anomaly caused by the lead sea-mount may cause the
    sea-level to be higher if the volume of water attracted toward the sea-mount
    collects in such a way around the sea-mount that it causes a "mound" of
    water that is "higher" than the total depression of the water surface over
    the sea-mount.  However, it seems to be asking a lot of gravity, even from a
    lead sea-mount, to create a "mound" of water.  The rapid decrease in
    gravitational attraction (inversely proportional to the square of the
    distance) and the insignificant difference between the vector sum of the
    attraction towards the sea-mount and the earth and the vector of attraction
    towards the center of the earth would both seem to make mound building
    difficult.
    
    Therefore, I think your original statement was correct, even for a
    sea-mount.
    
    George Istok
    
    -----Original Message-----
    From: Navigation Mailing List [mailto:NAVIGATION-L{at}LISTSERV.WEBKAHUNA.COM]
    On Behalf Of George Huxtable
    Sent: Friday, August 15, 2003 11:05 AM
    To: NAVIGATION-L{at}LISTSERV.WEBKAHUNA.COM
    Subject: Re: Navigating Around Hills and Dips in the Ocean
    
    In an earlier mailing today, replying to Sharon Casey, I said-
    
    >Above an underwater sea-mount made of lead, there would be an increase in
    >gravity, and >the sea-level would be a bit lower there than it would be if
    >the lump of lead was absent.
    
    Thinking about it a bit harder, and perhaps a bit more clearly, it now
    seems to me that I got the last bit quite wrong and should really have
    said-
    
    "Above an underwater sea-mount made of lead, there would be an increase in
    gravity, and the sea-level would be a bit higher there than it would be if
    the lump of lead was absent."
    
    That error doesn't affect anything else in the argument, but it's better to
    get these things right rather than wrong.
    
    George.
    
    ================================================================
    contact George Huxtable by email at george---.u-net.com, by phone at
    01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy
    Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    ================================================================
    
    
    

       
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