Great site for strong ground motion reports. I won't trust anything from this last earthquake because of the soft soils, but the Chile report is interesting.
Santiago gives complex signals, so I suspect there is a strong basin effect.
When you integrate you get displacement, which I would use as an input for my dynamic model.
These were at a PGV of about 50 cm/s
I am now cutting myself off from NZ, since it is very sad, and there is nothing to be learned here.