What occurrence could completely submerge a city- let's say Los Angeles- relatively quickly without actually causing a great deal of damage to it in the initial process? (A little like Atlantis. But in Los Angeles. Los Atlantageles.

This would be in modern times, or the very close future (within the next few decades). Something somewhat scientific would be preferable, though if it floods LA and makes sense- then it's fine.

For example, I was initially thinking about things like global warming, and the ice caps melting. But this process seems far too slow- as the sea levels wouldn't jump a metre overnight.

I'm out of ideas. It's worth pointing out that LA would need to be permanently (or at least for a very long time) submerged. This is why I'm stuck. So either the entire ocean rises, or California sinks.

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    $\begingroup$ Welcome to the site blue. Can you provide us some framework for your question? Do you want a scientific explanation, will psuedo-science do? What resources are available to do this? What era are we in? (modern/ancient/far future) If you can constrain your question a bit we can get you an answer, but as it stands there is nothing to differentiate two good answers as 'correct' $\endgroup$
    – James
    Apr 13, 2016 at 19:27
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    $\begingroup$ Note that the close vote doesn't mean its a bad question just that we need a little more info first and we don't want people answering a question that may drastically change (thus invalidating their answers) before it is finalized. It can be reopened once it has been updated. $\endgroup$
    – James
    Apr 13, 2016 at 19:28
  • $\begingroup$ Now that it has been edited, I would vote to re-open it. I do ask, for clarification, how deep Los Atlantageles is to be flooded, and must it be the entire city (the city tops out at about 1500m - we don't have enough ice on Earth to cause that level rise)? Also, are other places affected? $\endgroup$
    – Mikey
    Apr 13, 2016 at 20:15
  • $\begingroup$ Los Atlantageles doesn't need to be entirely submerged- and the tops of skyscrapers can rise above the water. I'd say that a large portion of the city needs to be submerged, but not all of it. And yes- other places can be affected if need must be. $\endgroup$
    – blue52
    Apr 13, 2016 at 20:28
  • $\begingroup$ I was tempted to answer just "water". $\endgroup$
    – Mermaker
    Nov 14, 2016 at 14:45

4 Answers 4


You could have an earthquake cause the land to split and then drop down where the city is. Essentially the plates would shift and start moving apart, creating a subduction zone where the city is.

It would be fairly violent but you could make it more slow and steady rather than sudden and violent and still be vaguely plausible. There is a hell of a lot about plate tectonics that we still do not understand which gives an author a lot of wriggle room to come up with things.

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    $\begingroup$ And most of the buildings are designed to handle earthquakes, so most should survive such a slow and steady event. $\endgroup$ Apr 13, 2016 at 21:30
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    $\begingroup$ you can use the reverse scenario like, if you want to submerge la then make everything near by higher ground. if due to earthquake whole of atlantic ocean plate were to come up then water will move to lower ground near by. $\endgroup$
    – Sp0T
    Jul 12, 2016 at 8:32

A tsunami could do this. Look at the video from the Japan 2011 quake. It wasn't a Day-After-Tomorrow 100 foot wall of water; the water just kept rising and rising and rising.

It will push heavy things around which will run into other things and cause damage, and some things will get upset and catch fire/explode, but structurally the city could survive pretty much intact.


How about a hurricane?

It's not unheard of for hurricanes to cross the Atlantic, pass over southern Mexico and continue into the Pacific. In our extreme climate change, one could very well gather strength and be pushed up to Los Angeles.

It would require 'the perfect storm' of events. The drainage infrastructure is blocked by debris, so stormwater drainage is unable to be pushed out efficiently as the hurricane dumps enormous amounts of water (and a storm surge). Downtown LA is under twelve feet of water.

A beautiful book, called Zaytoun, based on true events during Katrina, described a man who was able to canoe around his neighborhood and see fish and an aquatic world below his second story window, after Katrina (a very different set of circumstances, but true that it was a series of different unfortunate events).

Unlike Katrina, Los Angeles is above sea level, but like many storm and flood events it can take weeks before floods recede 'down hill.' For the first few days, it was described by the person as like an aquarium. Later, though, of course detritus filled the water.


Over several decades, the Antarctic Ice Sheet broke loose and slid into the sea. This provides a sea rise of about 180 feet. If the same thing happened to the Greenland ice, you'd get another 20 feet. This will not submerge all of LA, but it's a start. To really do the job, you need about 400 to 500 feet of water, and this requires a major subsidence event, which is most unlikely to be graceful. Massive earthquakes are pretty much inevitable.


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