How can a sea, such as the Mediterranean, be tideless?

The Mediterranean does have tides. They are just less noticeable.

” Tides, like many of the phenomena in nature, are very complicated in their details. If the Earth and Moon were both perfectly spherical and the Earth was covered by an ocean of a constant depth, then everywhere the tides would have the same amplitude. However, the Earth has continents and islands and the oceans vary greatly in their depths. All of these things affect the amplitude of the tides seen in a given spot, as does the local climate and air pressure!

The Mediterranean sea does have tides, but they are of a very low amplitude, as you can see somewhat in the below diagram (from Legos via Aviso/Altimetry) where the Mediterranean is mostly shown in blue meaning its tides have an average amplitude of a few centimetres, (instead of the metre of so shown in the part of the atlantic you can see). ”

Curious About Astronomy

It may be worth noting that dry land also rises and falls with the tides, subject to the same gravitational effects. But for land masses the amplitude is only about ⅓ that of water tides.

@gasman what is the reference point for dry land rising and falling? What’s the fixed point you measure it from?

@jazzticity Sorry I have no links or references. But I know that extremely precise ranging of earth-moon distance are made using lasers shined off reflectors placed on the moon’s surface by Apollo astronauts, and these demonstrate (among other things) tidal effects.

@gasman, okay, makes sense. I know they have ways of measuring things that just baffle me.