In one, I'm in Taiwan (at least ca. 1976 Taiwan, when I was there) when the Tsunami hits it. I think that's my mind supplying the closest thing to the real area it can furnish from places where I've been.
Last night, I was in a place that looked like a cross between coastal Washington and Honolulu ca. 1959. The skies were gloomy with rain, and a high surf was up on "the wine-dark sea." And I saw the sea rise up, far out on the horizon, and realized I saw the tsunami coming. It was too close to try to outrun, so I ran into the big old stone hotel building, and headed for the upper floors. I felt the shock of the water hitting, when I was on the second floor hallway, and was glad I was in an interior hallway, away from the windows of the rooms facing the sea. But then I looked up, and saw the ceiling bulging, caving in, and realized there was a ballroom above, and it must be full of water. I was desperately running down the hallway so I wouldn't have the ceiling with the water above fall on me, when I woke up.
At least, having had so many of these sorts of dreams, it's a familiar angst. I know what lives in my anxiety closet, and it's something worthy of being a nightmare.