Weird tides

[Ken Logan]

Can anyone tell me why there are no tides in places like the
mediterranean or the Baltic ? I understand about the effect of the
moon to create tidal pulls but why not on every large stretch of
water? I was asked yesterday and was absolutely beaten by the
question.

Thanks for any help posted.
Always be courteous and diplomatic.
Let other people have your way 8-)
e-mail replies to
k...@bingley.demon.co.uk.

[Carl Fink]

On Sat, 18 Jul 1998 16:52:19 GMT, Ken Logan <k...@bingley.demon.co.uk> wrote:
>Can anyone tell me why there are no tides in places like the
>mediterranean or the Baltic ? I understand about the effect of the
>moon to create tidal pulls but why not on every large stretch of
>water? I was asked yesterday and was absolutely beaten by the
>question.

There *are* tides on the Baltic and Mediterranean. There are tides on
the American Great Lakes, for that matter.
--
Carl Fink ca...@dm.net

So, who else is going to be at WorldCon?

[Lauri Levanto]

Ken Logan wrote:
>
> Can anyone tell me why there are no tides in places like the
> mediterranean or the Baltic ? I understand about the effect of the
> moon to create tidal pulls but why not on every large stretch of
> water? I was asked yesterday and was absolutely beaten by the
> question.
>

> Thanks for any help posted.
> Always be courteous and diplomatic.
> Let other people have your way 8-)
> e-mail replies to
> k...@bingley.demon.co.uk.

There is tide even in Baltic. It is about one inch at highest.
I know a couple of narrow straights, where a barely noticeable stream
changes direction in tidal rhytm.

Think the Baltic in göobal scale. The whole area is within
the rising tide zone at the same time. There is no place
to draw the water from.

- lauri

[John Holmes]

Ken Logan wrote in message <35b0d2a...@news.demon.co.uk>...

>Can anyone tell me why there are no tides in places like the
>mediterranean or the Baltic ? I understand about the effect of the
>moon to create tidal pulls but why not on every large stretch of
>water? I was asked yesterday and was absolutely beaten by the
>question.

There are tides. They are just smaller.

If you think in terms of the vectors for the moons gravitational
attraction, and the angle they make with the Earth's surface:

For a large body of water like the Pacific Ocean, the moon will be
pulling vertically on one part of the ocean (from where it is overhead)
and near-horizontally on the other edge of the ocean (from where it is
on the horizon). It is the difference between those two vectors (roughly
speaking) that causes the large tide.

For a smaller body of water like the Mediterranean, the difference
between the vectors at the eastern and western ends is not so large, and
so the tides are smaller.

Think of the size of the body of water in terms of its longitude extent
as a proportion of 180 degrees (the curvature of one side of the Earth).
That should give a rough idea of relative scales.

Regards,
John.
hol...@smart.net.au
email copies of any replies would be appreciated.