From 6.5 to 5.5 million years ago, the Mediterranean Sea underwent what scientists called "The Messinian Salinity Crisis". In basic description, some geological force (I'm not sure what) simply...

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...dried it up.

The key to this question is that with a major body of land reduced to land, passage is open for animals to colonize new lands. Turning lots of water into land is, at first, the most convenient.

The thing is, the Crisis happened only once. Once the waters from the Atlantic broke through Gibraltar, the Mediterranean stayed a sea for the last five million years. For the sake of animal migration, in an alternate universe, should it make sense for the Mediterranean drying up only to refill with water to be a cyclical event, preferably earlier than seven million years? Or should I stick to travel via wind and rafts, as had often happened more than once?

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    $\begingroup$ Can you edit this a bit? It's extremely confusing to read, and I'm not sure what you're asking. $\endgroup$ – AndreiROM May 2 '16 at 1:23
  • $\begingroup$ Edit it a bit how? What were you expecting? $\endgroup$ – JohnWDailey May 2 '16 at 1:51
  • $\begingroup$ Are you asking whether the Mediterranean dries up in cycles from a geological perspective? Or are you asking whether it would make a good story point? $\endgroup$ – Schwern May 2 '16 at 5:37
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    $\begingroup$ It would be quite easy to create an alternate world in which this is cyclical. Simply have the sill at Gibraltar be above the low sea level during ice ages, but below sea level during interglacials. The open/close cycle will thus repeat until the sill erodes. If the sill is a hard rock, or there's uplift that matches the erosion rate, that could be a long time. $\endgroup$ – jamesqf May 2 '16 at 17:40
  • $\begingroup$ Could you rewrite the question in one clear and preferably short sentence? And add it at the end. $\endgroup$ – Vincent May 2 '16 at 20:15

The closing of the Mediterranean was a result of plate tectonics, and the movement of the African plate relative to the Atlantic and European plates (yes it is more complicated than that, but for simplicity imagine only three plates for now) created the conditions that closed, and then later opened the mouth of the Mediterranean.

Since this works of the scale of millennia, and is not cyclical or repeating, making this a periodic event is not going to happen, or at least not on any sensible timescale. Fro example, XKCD's comic "time" is set 11,000 years in the future (to see it as a movie, go to this link: http://xkcd.aubronwood.com), where the Mediterranean is reopening after being closed for several thousand years.

As an alternative, if you really want to have the Mediterranean closed again to create dry land, a proposed mega engineering project called "Atlantropa" postulated damming both ends of the sea and allowing it to evaporate to generate massive amounts of hydroelectric power and create massive new tracts of land for farming and industry. Once something like this gets underway, plants and animals can be expected to start colonizing the newly exposed land (to the fury of farmers) and of course we now have pathways for invasive species to travel between Africa and Europe (to the fury of everyone).


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AFAIK the Mediterranean has been closed and dried out (and then reopened and flood back) at least six times. A record of salt strati separated by layers of continental deposits is very clear.

The keyword is salt. Once the Sea closes and dries up it is way more lifeless than the Death Valley. I cannot imagine a lifeform able or willing to colonize this hot, saline, and dry terrain.

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  • $\begingroup$ en.wikipedia.org/wiki/… $\endgroup$ – JohnWDailey May 2 '16 at 12:44
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    $\begingroup$ Death Valley is far from lifeless, especially if you look at the mountain slopes surrounding it rather than just the absolute bottom salt pans. $\endgroup$ – jamesqf May 2 '16 at 17:36
  • $\begingroup$ @jamesqf Not to mention that the salt plains are pretty much flat. That certainly wasn't the case with the Mediterranean drying up - a lot of the land wouldn't be overly salty, only the few hotspots (the last isolated areas to dry up) would be truly horrible. For a time. $\endgroup$ – Luaan May 11 '18 at 7:19

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