Re: [Phys-l] One half of a tide?

[chuck britton <britton@ncssm.edu>]

Fascinating - looks like it happened back in April too.
'Most of' the gulf of Mexico (usually) has only one tide per day.

But it's fun to scan around the coast of Florida to see how it varies.

Charles Babbage chose in interesting and commercially important  
project for his calculating machine to address.

And Lady Ada did a fine job of implementing his ideas.



On Aug 12, 2009, at Aug 12(Wed) 10:43 , John Mallinckrodt wrote:

> Yesterday I just happened to pick up a tide table for the Ventura
> area (where our vacation single-wide is located) and noticed what I
> was initially quite certain was a mistake.  The tide table indicates
> that the usual two tides (four tidal extrema) a day routine would be
> disrupted this Friday (August 14, 2009.) On that day there the table
> indicates no low tides at all and only one high tide in the late
> afternoon.  That is, the prediction is for just one half of "a tide"
> on Friday.  It turns out that the tide table is correct.  The
> following link to a graphical tide table shows how it works:
>
> http://www.freetidetables.com/state/California/sid/14557594
>
> Notice that Friday happens to be one of the very rare days when the
> lower high tide (in the wee hours) happens to be lower than the
> higher low tide (at dawn).  But compounding the rarity even further,
> the previous low tide occurs at 11:23 PM on the 13th (37 minutes
> before the 14th begins) and the next low tide occurs at 12:39 AM on
> the 15th (39 minutes after the 14th ends.)  The result is a single
> tidal extremum at 4:19 PM on the 14th.
>
> John Mallinckrodt
> Cal Poly Pomona
> _______________________________________________
> Forum for Physics Educators
> Phys-l@carnot.physics.buffalo.edu
> https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l