Revelations from Keynote II

[ObsidianFire]

If they were identical copies could it follow that locations are, to some extent, similar, even if they've been somewhat altered in some way as a result of those calamities (as in, somewhere is still identifiable as City X but that wall over there is in a different place)?

I'd say probably not. Calamities are more then just... an earth-quake. We're not talking, "cities are laid out differently" kind of differences. We're talking "continents are in different places with different climates" differences.

This is especially true of the first several umbral Calamties. The 1st Calamity was so long ago that no one knows what the world was like before it. Just that it was a total "system reset" of society and politics. And to make matters even more interesting, no one apparently knew about magic back then.
The 2nd Calamity was a year long volcanic eruption that blotted out the sky with smoke and ash and lightning. Mankind fled into caves to wait for the skys to clear. They called on the Twelve which lead to them discovering magic at this time. And again, there's a "system reset" of society.
The 3rd Calamity was when the sun grew huge and dried out the world. Crops failed for years and many lush green areas became wastelands. It's currently thought this is when the region of Thanalan became like it is today.
The 4th Calamity wasn't a natural disaster so much as it was a societal one. The power generator of the Allagan Empire was broken by a gigantic earthquake and the Allagan capital was swallowed up by the earth. This lead to the collapse of the Allagan Empire and another "system reset" for society.
The 5th Calamity was essentially an ice age. Glaciers covered much of the land and icebergs were common place. This probably was even worse in Ilsabard as it's further north then Eorzea is.

So the Source has had all this stuff happen to it, while the Shards probably have not. If anything, the Shards probably don't have the "system resets" the Source does when it comes to culture, so they probably have a more modernized lifestyle. Their land probably hasn't been through anywhere near the abuse the Source has either. Or if it has, it's probably on a much more localized scale and they probably didn't get hit with all of these.