How to get a world with polar seas

[Thornir Alekeg]

I think the only problem is the idea of isolated lakes or small seas. Where does the water come from to fill these? It is unlikely that a world will be so even topologically that there would be few places where water would collect and eventually connect into larger systems. If the world is so dry to prevent this from happening, why would there be water there in these seas in the first place? If everything else were so dry, evaporation would be rapid so it is unlikely that these seas and lakes would persist without a replenishing source. If rainfall is frequent enough to replenish the lakes, it should also make water more readily available elsewhere.

 

[Angel Tarragon]

Go to this website for some amazing sculpted globes and maps of alternate Earths:

http://www.worlddreambank.org/P/PLANETS.HTM

That is an awesome website. Thanks for posting the link, otherwise I'd still be in the dark. I am totally using those alternate 'Earths' in the next Tangents game I run.

 

[Technomancer]

Topographically, there's nothing inherently farfetched about having seas at both poles. The problem is having temperate poles and a cold equator. It's really hard to see how a planet would be cold at the equator and hot at the poles, but here are some nearly-plausible scenarios, maybe just enough to suspend disbelief for a fantasy world:

1. Volcanic hot spots at the poles that keep them warmer
2. A torus of debris around the planet's equator (maybe a destroyed moon) that reduces insolation at lower latitudes but doesn't affect the polar regions
3. Extremely high plateaus or mountains at the equator, like a belt encircling the planet (think 10,000 Kilimanjaros or a vast Tibetan plateau)
4. The planet has an axial tilt of 90 degrees, with one pole pointed at the sun, and the other at a "hot jupiter" companion star. So the poles are always "noon", and the equator, twilight.
5. Equatorial volcanoes that constantly barf out ash into the stratosphere, circling the equator like a belt and cooling lower latitudes.

Rel's suggestion for a large axial tilt would actually make each hemisphere a dark, frozen wasteland for half a year, and bathed in dazzling sunshine for half a year. Just like our own polar regions, but covering a larger area and more extreme.

Go to this website for some amazing sculpted globes and maps of alternate Earths:

http://www.worlddreambank.org/P/PLANETS.HTM

Yeah, I did want a hot equator, but man that is one awesome website. Thanks!

 

[Bayushi Seikuro]

Meteor, eh? That could create the lower elevation at one of the poles, shift the orbit...and create a supernatural cataclysmic event for the superstitious natives to base their calendar on. Very nice.

The other reason I mentioned a meteor is it's something that's been kicking around in my head for a game.

The meteor would also be, in theory, the basis for a region where there would be strange metals and crystals - mithril, adamantine, etc. And, by being extraterrestrial, it might make that area innately dangerous - in the game I'm thinking of, the impact brought a strange sickness, making an almost viral zombie outbreak.

Again, my two cents. A lot of good ideas floating around here though.

Another idea - I apologize in case I'm misreading things - would be to completely go nonscientific. If you want hot equator and temperate poles, with the vast seas at the poles. What about changing back to the old theory that the Sun (or Suns?) revolve around the planet? For some reason I had the idea of two suns revolving around the equator, but that creates a situation like Pitch Black -- pure daylight constantly at the equator, twilight at the poles constantly.

 

[Aexalon]

For the impact scenario to lower the terrain under the average elevation level (gravity-wise, not geometrically, as worlds flatten a bit since they spin), look no further than our close buddy Mars, who in its distant past got a big wallop almost (more or less) straight onto its northern pole. observe the colossal world-spanning impact basin that, on the more-or-less other side of the planet is matched by a volcanic highland and the solar system's biggest crack (no pun intended). Scale it up, add cometary ice, move closer to sun, and you'd have one very habitable pole (ok, some atmpospheric issues remain). The odds of such a thing happening on both poles of the planet are quadratically remote, of course ...

Disclaimer: statements about Mars may derive from crackpot theories.

For an entirely different take, look at Illuin & Ormal, the "Lamps of the Valar" in Tolkien's work, two lights on opposite sides of the world. Of course, Arda was rather flat then, so the applicability is ... limited

 

[Rel]

Alternatively, if you're interested in solar peas, you can take a large lens and focus it on a pot of water and probably get it to boiling eventually.

 

[JDJblatherings]

I used to end up with polar seas and dry temperate and equitoral zones now and again when playing simEarth. Certainly possible with a plausible degree of science in an rpg world if it can happen in that game.

 

[tzor]

How would a world that was completely dry except for a large sea at each pole be formed?

In order to get such a world in the first place you need a number of conditions. The most important of them being a complete lack of plate techtonics. Assuming that you have these conditions you are going to have one small poblem with your world. You've just created a variation of the planet Dune.

You see, without a sea in the middle of your planet there is nothing for clouds to form from, except at the poles. Winds generally follow the orbital flow of the planet, and often strong winds circle near the polar regions. (Antarctica is known for these winds around the end of the continent.) A second souce of water vapor, volcanic action is prevented because of the lack of plate techtonics. (Because cracks in the earth would funnel the water away from the poles. Note on earth all major oceans are over cracks in the plates where they are the thinnest.) No clouds means a generally hotter and completely dry environment.

 

[Jeremy757]

How would a world that was completely dry except for a large sea at each pole be formed?

By my admitedly limited knowledge of how these things work, I would start with a frozen world covered in ice with the highest elevations at the equator gradually sloping downward to the poles. Cue solar flare or shift in orbit or something that makes the planet a lot hotter, ice melts and flows toward the poles, leaving a big dry expanse between the poles (with maybe isolated lakes or small seas somewhere between. Logical? Possible?

If this is for a D&D or fantasy game, you don't need an explianation. The world has always been that way for as long as anyone can remember. The people in a fantasy world wouldn't know about or understand the geological evolution of a world anyway.

 

[dougmander]

Yeah, I did want a hot equator, but man that is one awesome website. Thanks!

Sorry, I misread your initial post, but, yeah, that is one amazing site -- he actually sculpts the surface features of those globes by hand and paints them!