You bring up another excellent point or three.

Duration is also a factor. Seconds vs. minutes can yield an order of magnitude of damage.

The frequency of the vibration can also have a role because of resonance. Small structures are more prone to certain vibrations than large ones or visa versa. Think of the glass that gets shattered by a singer. The shape and size of the glass can make it more or less prone to shatter when the singer hits that critical note, so it is with buildings.

So no two quakes are the same, which makes things more interesting.

(By the way, I loved the Thunderbird preface to the link Don provided!)