Imagine, if you will, a volcanic eruption on the Atlantic side of the Straits of Gibraltar. The eruption is copious, but does not present a flood basalt like the Deccan Traps or the Siberian Traps. Over the course of about 5 years the western entrance to the Med is blocked.
What happens? Can we construct a sufficiently large canal going through Spain or France or Algeria? Should we? What about the salinity of the Med? What about geopolitics? And how would it affect the climate?
We could use such an event to move forward with this plan to dam the straights and lower the Med waterline. (The original plan also included further European subjugation of Africa, inundating Lake Chad and flooding much of the Congo.)
Who is this “we” you speak of?
Presumably your volcano remains active and dangerous enough that “we” couldn’t simply scoop out lava and continue to use the existing straits?
How difficult a canal would be depends on where this volcano appears and how big it is, and therefor how long a detour is needed.
My guess is that Spain and Morocco would both compete like crazy to get a canal on their territory. It would be incredibly lucrative. And I don’t know enough about the local geography to know which would offer the eaiest build.
There’s already a canal going through France. I believe it’s of less than optimal size, though.
That plan would also require constructing locks on the Suez Canal and somewhere on the Dardanelles, so that both of those could continue to be navigable.
Well even the Aswan Dam is effecting the salinity of the Mediterranean so any closure of the outlet to the Atlantic would be horrific. If a simple dam can change the salt in a sea, imagine what that could do.
I understand your concern with Suez, but why the Dardanelles? Aren’t the Mediterranean and Black Seas at the same level anyway? Or is your worry that the level of both would drop enough to make the Dardanelles impassable for significant traffic?
Yes, I suspect that the Dardanelles would become too shallow.
Wow! No thought as to the added salinity, I see.
It is my understanding the straight has been closed many times during geologic history and the Med dried up many times in Earth’s long lifetime.
Great question.
The Suez Canal would suddenly become incredibly geopolitically important, with Egypt in the driving seat. There would be yet another upheaval in the Muslim world as various religious/political factions attempt by means fair and foul to gain more control of the canal and/or the Red Sea.
The problem of Somali pirates would also become a much greater priority, and I suspect you’d see more military action in the region and a greater public and political tolerance for sinking them.
Would the flow of water be such as to erode the canal significantly? Or too great to allow passage?
Surely the canal would become unimportant, as the route to northern Europe and the Americas would be forced back round Africa. Eventually the Med would dry up altogether, despite a net inflow from the Black Sea, nless Suez was allowed ot become a raging torrent.
What sort of cargo goes by ship to and from northern Europe, through the Mediterranian and Suez Canal, and where is its final destination? Rather than going around Africa, someone might find a cheaper solution by building a port on the Med, then transporting by land.
Oil tankers. Container ships full of Chinese crap. Bulk carriers full gain ore iron ore. In fact pretty much all bulk European -> Asia / Australasia trade.
It would probably be cheaper to build a new canal than to widen that to Panamax standards.
Every kind of commodity you can think of, to and from the middle east and India, for example.
Bill Bryson talks about this issue in “A Brief History of Nearly Everything.” The climate changes when the Med dries up, although the effect would probably be gradual on human timescales.
Yeah, but anything destined for Europe doesn’t really have to go through the Strait of Gibraltar. I know there’s a huge port in Rotterdam, but if the strait was blocked, would it be worth it to go all the way around Africa, or would they start looking to develop ports along the Mediterranean coast of Europe? Crude oil still has to get to the refineries, so that may be worth taking the long way around. But it seems to me that they could build container terminals and still use the Med/Suez for things like that.
If the Mediterranean dried up, what would that do to sea levels in the rest of the world, or is there not enough water in the Med to make a difference?
The Messinian Salinity Crisis.
That Wiki page claims up to 10m rises in global sea level.