Tilted Earth Reconstruction by Depperoni

[rdanhenry]

I...actually don't have any general way to work out the circulation, honestly.

I'm pretty sure nobody does. I mean, there are computer models, of course, but it's too early to really judge them. There's been a relative explosion of deep-ocean data in recent years, but anything that deals with the deep ocean is still working with limited information and when we are still trying to work from a general to detailed understanding of what actually happens, trying to answer counterfactual scenarios leaves a lot of room for speculation.

Of course, half of "hard" science fiction is recognizing when you're violating known science so you can cover with some technobabble (ideally with something that's at least superficially plausible, like "the water warms here because of extensive underwater vulcanism") or sidestep entirely as so normal in the setting as to be accepted without comment.

The formation of deep water is governed by density, which is a balance between salinity and temperature, both of which are governed by wind-driven surface evaporation. So...
1) Fast wind and freezing temperatures both cause water to become colder and saltier, and therefore to sink; hot rainy climates make it warmer and fresher and therefore less dense. (Hot dry weather and cold rain both have less effect, obviously)
2) The water that sinks to the bottom flows downhill, and flows away from the points where it sinks from the surface; water is "produced" at the rainy tropical latitudes and flows toward the points where it sinks.

I don't know what you can do with this -- I have to go do other science but I'll be back later. :-P

I think a few general rules like this are the best you can do, especially without trying to map out the entire sea floor and run a resource-intensive simulation. We can certainly say that certain proposals would definitely not be at all likely, so the rules can keep from creating something implausible, but I think there's still going to be a lot of wiggle room to assume things flow in ways that are productive of the situations desired by the author.

[octopod]

Well, of course we don't have a complete general circulation model yet, but I've got the impression that the GCMs we do have are good enough to predict the major features of world ocean circulation. But really that's immaterial, unless Depperoni is willing to run GCMs of this world on some computer cluster or another, lol.

Really, I was mostly hoping someone on here who's the right kind of geoscientist could step in and give better guidelines than I could come up with off the top of my head. Surely there are plenty of other geo types on a site like this, right?

[Depperoni]

Pfew... finally got my continental margins, everything down to 500 meters:
tiltshallowseas.jpg
Good marine elevation maps of Antarctica are so scarce, I had to use my imagination as well, but the rest is pretty acurate.
I suddenly have a job and a well filled agenda, so I won't be posting as much as I thought I would
Rest of the topography is coming up (don't know when though....)

[Depperoni]

woops, I just found out I forgot some part West of Florida
tiltshallowseas.jpg
corrected

[lajosb]

Have you seen the tilted earth maps here?:
http://www.worlddreambank.org/T/TILT.HTM

[Depperoni]

Oh wow! That's perfect
Thank you a lot!

[Depperoni]

I've drawn two sketches of air pressure, kinda based on maps of the real world, but pretty intuitively.
The black lines are 1014 hPa
Low pressure runs to 1010 and 1000
high pressure to 1018, 1022, 1026 and 1030

The first one is january
pressuresketchjanuari.jpg

The second one is july
pressuresketchjuli.jpg

What do you think? Does it look natural? Anything that really doesn't fit?

(Ignore the attached thumbnail, I don't know how to remove it...)