When the Mediterranean evaporated
So... The Mediterranean Sea has dried up in the past.
Wait, what?
Yep, all of the water in the Mediterranean Sea evaporated...
The rate of evaporation in the Mediterranean is really high. In fact, it is three times higher than the rate of influx of water from rain and runoff. Usually this isn’t an issue as the Mediterranean is also topped up by the Atlantic Ocean. However, about six million years ago the African and European continents collided. This caused the Strait of Gibraltar, the entry into the Mediterranean, to close over. When this happened the Mediterranean was cut off from the Atlantic, could not get topped up anymore, and the excessive rate of evaporation from the glare of the Sun did the rest.
It actually took only 2,000 years for all of the water to evaporate, creating a desert where the Mediterranean Sea had been.
This isn’t just conjecture, by the way. We have proof.
Firstly, when the water evaporated, it was literally just that, the water, that was removed. The salt from the salty sea was left behind. There are massive amounts of salt left behind from the Mediterranean drying up. Half a km under the island of Sicily is an absolutely huge salt mine, where 500,000 tonnes of salt are mined every year. There is so much salt there, that it is estimated this rate of mining could be continued for another million years. Now that’s a lot of salt!!!
Secondly, there are huge crystals of gypsum in underground geodes. The crystals, more than a metre long, were formed when seawater trickling down from above met hot waters coming up from below. The fingers of gypsum grew (and grew and grew) in this mineral-rich mixing zone. They would have stayed submerged if the level of the Mediterranean Sea hadn’t dropped.
Want more evidence? How about the fossilised remains of dwarf elephants found in Sicily? Wait, what? Yep, that’s right. There are fossilised remains of dwarf elephants found in Sicily. The elephants were able to walk across the dry Mediterranean. But then when the sea returned they were forced to take refuge on higher ground, on what would become the island of Sicily. As an island, there was a lack of space and food. Over time evolution led to a decrease in size.
Now here’s the extra bit - the Mediterranean Sea has actually come and gone many times in the last few million years. We think of it as being too much of a stable geologic feature, but that’s just in our limited human history, which is really just the blink of an eye in the grand scheme of things...
Cool, huh?