Board Thread:General Discussion/@comment-70.72.38.180-20150328175811/@comment-25857155-20150401164059

Or maybe a chunk of the moon landed on it and squished it.

Or....

Maybe the moon had a base set up on it, with a big weapon of some kind. When it was about to fire, A special operations group was forced to blow it up to save [insert one of the Kingdoms here], and ended up blowing up the moon. As a result of the moon being partially exploded, the tides of Remnant got jacked up, causing the sea level to rise above the level of the continent. (Closer to my headcanon.)