I recall that the area of the harbor is an old volcanic center; late Miocene I think (>5 million years). I could be wrong on this. But, I wonder whether the moment release was indeed shallower than the M7.1, and this is partly because the other quake was in the cr*pola rocks that make up part of New Zealand and that these rocks have less strength (caution, fairly high level of speculation here).

I am also curious about frequencies of these accelerations. If over 100% of g, things like rocks (or boulders) can be tossed in the air, at least a little ways. But, how big an object can be tossed might logically be related to the frequency of the ground motion.

I again may be wrong, but a hard rock site right above the hypocenter, like where the 220% g was measured, might be expected to have high accelerations, but with higher frequencies?

I don't know if it is true, but I heard/read that boulders were moved some distance wothout leaving any drag marks during an 1890s(?) M8+ quake along the Himalayan front.

Chris