Long ao, a philosopher wrote about a city called atlantis. This nation was a dominant force in the world until it lost a war with Athens, sinking into the sea. However, the simple minded buffoon got his information wrong, for the texts in which he based his story upon refer to an ancient nation called Ryleth. This landmass was the size of modern day Texas, and sank due to an ancient flood.

This civilization worshipped a deity called "the crawling chaos", and was located somewhere within the strait of gilbatrar. The inhabitants created the institution of benevolent slavery, and took control of humanity's future for its own good in order to add worth to their pointless lives. However, this pathetic species betrayed their masters in a war, causing Ryleth to submerge.

Now is the time for the continent to rise from its depths and take its place as the dominant power of the world. Survivors of Ryleth have performed a telekinesis ritual which will cause it to rise to the surface from the bottom of the sea in a matter of days. Soon, the crawling chaos will wipe away all false religions, and humanity will sing and dance at the return of the one true god.

What effect would a quickly rising continent have on the planets geography?

Edit: I changed the size of the continent to mimic a large state.

  • $\begingroup$ Over what geographic extent, and what time period? $\endgroup$ – Spencer Nov 23 '19 at 13:39
  • $\begingroup$ Also, how was it submerged, and how is it "rising"? Is there dirt beneath it piling up, or was the flooding over the city now going to recede? It seems this question is too broad right now, as a "rising continent" could be small and fast, large and slow, or literally anything in between. The effect could be anything from "basically nothing" to "entire world-wide changes". $\endgroup$ – cegfault Nov 23 '19 at 13:42
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    $\begingroup$ The straits of Gibraltar are small and well understood and thoroughly mapped. I'd consider somewhere a bit more remote. Also, and perhaps more importantly, Australia is big. Really big. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to Australia. You can't just lose something that big, even in the Atlantic. I'd scale it down a bit. $\endgroup$ – Starfish Prime Nov 23 '19 at 13:53
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    $\begingroup$ @Spencer given the suggestion that the continent was the size of Australia, then unless if was rising geologically slowly (lets hope the crawling chaos is patient, eh?) then you'll get the biggest tsunamis since Chixulub. I guess that's one way of wiping away the false religions, though. $\endgroup$ – Starfish Prime Nov 23 '19 at 14:05
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    $\begingroup$ An emerging continent the size of Australia would displace rather a lot of water so all lowland areas around the planet will be flooded. I guestimate 70m++ based on the flood capability of a melted Antarctica $\endgroup$ – Slarty Nov 23 '19 at 16:00

Well, the story can't be literally true. A continent the size of Australia will not fit "within the straits of Gibraltar", because its area, of almost three million square miles, is several times larger than the entire Mediterranean Sea, which is just under a million square miles.

However, there is an event in the ancient past that could explain all of this. Geology shows that the Straits of Gibraltar have opened and closed several times in the last few million years, and when they are closed, the Mediterranean will mostly evaporate within a thousand years. The last time they opened, the Zanclean flood refilled the Mediterranean in about a year.

The dry bed of the Mediterranean would have been a strange environment, with vast deposits of salt and lakes of brine, unsuitable for modern-day animals and plants. However, it would have been very suitable for the creatures that worshipped the Crawling Chaos, who have survived in artificial habitats beneath the bottom of the sea, waiting for the stars to be right and make their ritual possible.

When that time finally came, the effects were drastic.

The closure of Gibraltar happened via massive earthquakes in Spain, Portugal, Algeria and Morocco. The British territory of Gibraltar was entirely destroyed. The tsunami in the Mediterranean stripped the Balearic Islands back to bedrock and did vast damage on the western coasts of Corsica, Sardinia and Sicily. Flooding occurred throughout the Mediterranean coastline, which was unprepared because of the absence of significant tides within the inland sea. In the North Atlantic, the Azores and Canary Islands survived rather better and the tsunami was weak by the time it reached North America.

The Turkish Straits and Suez Canal became rapids within a few weeks as evaporation began to lower the sea level of the Mediterranean. This disrupted commerce within Turkey and the Black Sea region, and between the Mediterranean region and Africa, India, China and Japan, and the closure of Gibraltar became a world-wide crisis. The idea of re-opening the strait before evaporation lowered the sea very far united all of Europe and Russia, plus Egypt and Israel, for a wide variety of reasons. Other countries came around to the idea as the effects on trade became clear.

Spain and Morocco made it clear that after the devastation they had suffered, using nuclear weapons to re-open the straits was not going to be welcome, not even a little, and one of history's largest excavation projects was started.

Humanity is unaware of why or how Gibraltar was deliberately closed, but it seems likely that a war will break out between them and the followers of the Creeping Chaos, once the ancient horrors notice that excavation is underway.


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