Headscratchers / Avatar: The Last Airbender - Geography

2 dimensional logic

• The Gaang needed to sneak into the Fire Nation undetected. Why didn't they go east from the Earth Kingdom? Word of God is that the map we see is the entire planet, after all.
  • Legend of Korra answers this with a proper image of the planet from space. Since we can see all the landmasses on one end, evidently it means there's a massive Pacific-Ocean-sized ocean on the other end.

Firebenders in the air temples

• How did the Fire Nation soldiers get to the air temples in the first place? They're built at locations really inconvenient for anyone who can't fly; namely, the underside of cliffs. We know hot air balloons were invented 100 years after, so that can't be the solution.
  • Maybe they still had dragons at the time, maybe they got their hands on some Flying Bison. Aang remembers there being dragons, so they obviously weren't extinct at the time.
  • Supplementary material also indicated some Airbenders betrayed their own people and assisted the Fire Nation.
  • Also, the tanks they use had a kind of cable that can be shot upward and used like a grappling hook, so that would probably work.
  • It’s also feasible that, even if they weren’t as advanced at the start of the war, they flying zeppelins and airships were sufficient to at least carry the soldiers up to the mountains.
  • The ostrich horses in The Avatar State could climb walls, Perhaps the FN had some animals like those.
  • When the northern air temple is attacked we see fire nation infantry traversing up mountain passes. Since the attack on the air nomads was likely a surprise, they likely had plenty of soldiers pose as pilgrims visiting the temple to observe the comet from a prime location while also having reserves hidden on the passes. Once powered by the comet and with surprise on their side, the fire nation may have been able to take the temples without air transportation.

Where did this waterfall come from?

• In the episode "The Waterbending Scroll" (1x09), the Gaang steals a boat and sail it downriver. The boat must then have come up from the river mouth, since it had originated at a sea port. How then does said river have a giant waterfall on it? The boat could not have sailed up the waterfall.
  • Who says that's the river's only route? Rivers split into tributaries and other canals and such all the time.

The seasons

• The seasons are very inconsistently portrayed. In the first book, for example, the Gaang are travelling from the South Pole to the North Pole. It’s winter in the southern hemisphere when they start out - the winter solstice takes place halfway through that season. So when they reach the North Pole, why isn’t it summer there? For that matter, the terms ‘winter solstice’ and ‘summer solstice’ are meaningless themselves without mentioning which hemisphere. Another example: in book 2, when the Gaang are in Ba Sing Se, which is on a fairly high latitude in the northern hemisphere, it should be autumn there, but it’s portrayed as spring.
  • The reason they refer to the entire world as going into the same season is because their world (like ours) is north-centric. In Legend of Korra, they resolve these discrepancies by showing outright that the southern hemisphere does experience its winter while the northern hemisphere is in summer.

Fire Nation... island?

• Why is the main continent of the Fire Nation called an island? It's bigger than either of the continents surrounding the poles.
  • Two possible reasons:

One, it uses the strict geological definition. A continent is a landmass that sits atop and moves with a tectonic plate in the earth's crust. An island is the result of volcanic buildup on the ocean floor, which is lower and more dense than the continental crust, that manages to breach the surface.

Two, the people of ATLA see the world as one giant landmass and surrounding islands, so the piece of land Ba Sing Se is on is called a continent, and everything else is an island.