Buda-Pesth, , 4to. Reprints and Permissions. The Tides of the Mediterranean. Nature 12, 43—45 Download citation. Issue Date : 20 May Anyone you share the following link with will be able to read this content:. Sorry, a shareable link is not currently available for this article. Most of the oceans of the world are subject to tides, which are caused by the combined effects of the gravitational forces exerted by the Sun and the Moon and the rotation of the Earth.
Tides cause the water level to rise and fall and, in doing so, the water is moved around causing a tidal stream which can sometimes be pretty fast! The difference in height between High and Low Water is known as the tidal range.
The bigger the tidal range, the stronger the tide. The highest tidal range in the world occurs at the Bay of Fundy in Canada with over 53ft 16m difference between High and Low Water. The second highest range is in the Severn Estuary in the UK; this can be as much as 50ft 15m with a tidal stream of up to 8 knots. Did you know that tidal forces affect the entire Earth, not just the seas, although the movement of the solid Earth is only centimeters? The reasons for this are a bit complex but basically it is due to their size and geographic nature.
These areas are described as Non-Tidal. Although they do actually have small tides they are not strong enough to be taken into consideration when navigating. Wouldn't the water rushing across the Atlantic all get trapped in the Med and "build up" because there's no way out? These bulges distort the shape of the solid Earth, and also distort the oceans. If the oceans covered the entire Earth uniformly, this would almost be the end of the story. But there are land masses, and ocean basins in which the water is mostly confined as the Earth rotates.
This is where rotation does come into play, but not because of inertial effects, as textbooks would have you think. Without continents, the water in the ocean would lag behind the rotation of the Earth, due to frictional effects. But with continents the water is forced to move with them.
However, the frictional drag is still important. Water in ocean basins is forced to "slosh around", reflecting from continental shelves, setting up ocean currents and standing waves that cause water level variations to be superimposed on the tidal bulges, and in many places, these are of greater amplitude than the tidal bulge variations. If you see me running, try to keep up. Geezer Naked Science Forum King!
I think there might be a simpler answer. The Mediterranean is really just a very big lake, big enough that it actually has tidal action, but nowhere near as much as the major oceans. It is connected to the Atlantic, but the connection is so restricted that tides in the Atlantic have little effect on the Mediterranean. Yup- No need calling Bill Nye for this one!
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