It wasn't inspired by Middle Earth nor do I think it's that similar to Arda (and I saw that post awhile back that showed a particular version of Arda (http://md.dndgamer.com/TOLKIEN/Arda.jpg) -- which is not at all accurate incidentally, Numenor is shaped all wrong, the west was done very differently, and the rest is pure speculation of what the rest of the world looked like.
Actually, there are a couple surface similarities between the Elemental map and Arda -- specifically, as Arda appeared in the First Age before the Valar overthrew Morgoth: Both continents were, like yours, joined by a land bridge at the very northern end(s), plus of course the large island in the middle of the sea (Numenor in Tolkien's world). That's really all I was referring to; I'm aware the geography is otherwise very different between Tolkien's world and your own.
By the by: Does that island in the middle of the sea have a name? I was just wondering.
Anyway, the map of Anthys (the part of Elemental we're concerned with) is a split between east and west with a natural barrier between them (water) with a half-way point (and island). It's not the most original way to split two factions apart but it wasn't inspired by Middle Earth.
Gotcha. Well I'd say it was about as good a way to split the factions as any, plus this way it's easy for the "casual" fan to understand.
I do really like the map, by the way; it has a lot of character. I do have just one other question, though: It appears the Greater Skarps and Imperial Spine likely form a single mountain chain (that briefly goes underwater between the two continents). I was curious as to whether that was deliberate, or if it just worked out that way?