This is a wonderful story of everybody shrugging off a distant, tiny earthquake. Anchorage is also on soup, like Christchurch, but they have a big earthquake in living memory, so we must assume that they don't have too many old brick deathtraps, since they all would have been knocked down in '64.
Still, if Chile came back, we must expect another big one hitting the place soon. There will be lots of soil movement and one heck of a tsunami. I hope they haven't been building soft-story condos!
The earthquake of 1964 was also noted for encompassing a lot of rock sites. These rotten government buildings weren't even scratched! Therefore, I would assume something like 5-10 cm/s on rock, and some very heavy amplification on the soil.