Dalamud

[ObsidianFire]

As far as I can tell from 1.0 screencaps, Dalamud stays in place once it starts falling past a certain point as it can be seen at all times of day or night. It stops rotating around the main moon and the planet and goes into geosynchronous orbit over the Lunar Transmitter (or whatever Nael ends up being). One it gets low enough, gravity does the rest.

Othard would most likely have seen Dalamud stop orbiting and freeze in place and then slowly drop over the horizon line all while the main moon acts as normal. Given how far Othard is from Aldenard (three months of sea travel at least (EDIT: whoops, two moths actually)), they probably wouldn't have seen Dalamud get anywhere near as big as Eorzea saw it get. It would probably be like watching something drop onto Rome from orbit from the point of view of Tokyo. It's possible that for a lot of people, Dalamud just vanished over the course of a day and was never seen again.

As far as Calamities go... Aldenard probably gets hit the worst. Silvertear is apparently the source of all aether and it's in Eorzea. It also probably depends on what Calamity is being talked about. The first five Calamities (Wind, Lightning, Fire, Earth, Ice) seem to have effected much more then just Aldenard in their scope. The sixth Calamity (Water) seems to be a lot more localized. I think it's still too early to tell if the last Calamity (Space) is large-scale or not. There does seem to be a trend of the Calamities becoming more and more localized until the 7th Calamity.

The Calamities of Wind (1st), Lightning (2nd), and Fire (3rd) all have to do with atmospheric conditions. The Calamity of Wind apparently destroyed everything and is what kicks off the Umbral/Astral Era dating system that is used everywhere. The Calamity of Lightning is the result of large-scale volcanic activity that lasts an entire year and is so intense humanity moves underground. The Calamity of Fire is the result of the sun getting bigger or burning hotter for a prolonged period of time. All of those would effect all of Hydalyen no matter the location, if in different ways.

The Calamity of Earth is a little different. The immediate earthquake effected the Mor Dhona region the most (the Allagan Capital is swallowed up), but the impact of that is worldwide. By then, the Allagans had conquered the three continents at least and Dalamud powered the Crystal Tower which powered the entire Allagan Empire. So in a single instant, the entire Allagan Empire lost power. It's not a world-wide geographical impact, but a world-wide sociological impact this time around.

The Calamity of Ice is said to frozen over the Bloodbrine Sea, north of Aldenard. It shares borders with Old Sharlayan and the southern Ilsabard Coast. It's also said that icebergs were found as far south as the Jade Sea which is South-East of Gyr Abania. It seems likely that Ilsabard was hit as hard (or harder) then Eorzea as it's further north then Eorzea is. I can't find anything about how Othard was effected by it.

The Calamity of Water is probably the most localized. It seems to have primarily effected the Twelveswood, Gyr Abania and Mor Dhona with overflowed rivers, lakes and tidal waves. Vylbrand is effected as well, mainly by tidal waves, but it seems to be more as a result of everything happening in Aldenard then the focus of the Calamity itself. What makes this one tricky to judge is that we hear more about the Mage Wars that lead up to the Calamity then we actually do about the Calamity itself. This is also the first Calamity that we hear of people who may be that era's Warriors of Light. While they couldn't stop the Calamity from happening, there are records of them saving a lot of people who would otherwise have died.

The Calamity of Space? maybe? Also known as the 7th Umbral Calamity. Parts of this Calamity are very localized, other parts are very widespread. While the debris field of Dalamud's fall is contained entirely within Eorzea, there's a lot of other, more subtle effects that will probably be felt the world over for centuries to come. Dalamud falling changed the heavens for everyone on the entire planet regardless of where they were. For one thing, Astromancy will forever be changed. Dalamud's position is important in star charts and Astrology and still needs to be calculated for everything to work out right. This Calamity was also partially blunted by Louisoix, the WoL, etc. It's safe to say the Calamity would have been even worse then it turned out to be if they hadn't gotten involved.

Basicly, Aldenard is always part of the effected region of the Calamities. The Calamities more often then not are large enough to effect places well outside Aldenard's borders though. Just because we don't have records of the Calamities happening in those areas, doesn't mean they weren't hit. Calamities almost always lead to the break down of the current society and records are really, really hard to find thousands of years after they're created... unless it's Allagan records...