[null and void]

True. A lot depends on resonance and where the peaks and nodes of standing waves occur. I had a nephew sleep through the Northridge quake in the top bunk, about a mile from the epicenter. They were on a node. Major damage within a mile or so on either side.

Mexico City is in some ways more vulnerable that it was in 1957, for one thing there are more tall buildings. So much water has been pumped out of the soils that they are now poorly consolidated and subject to collapse. (OTOH, I'd guess this would also reduce liquefaction risk a bit).

The right ground shake frequency (about one cycle per 2.5 seconds) will ring the ground like a gong. Any buildings with the same resonant frequency that are anywhere near the peak shake zones will get the bejabers shaken out of them!

Luck of the draw. A lower magnitude quake at the right frequency can be more damaging than an untuned larger one.

I wouldn't completely discount a 5.7, not for Mexico City anyway. But you are correct: generally a 5.7 is enough to rattle nerves and break some stuff, but not particularly dangerous.

[grey_whiskers]

Thanks for the info.

Cheers!

[dalereed]

i’ve been through every quake in Los angel es since and including 1952 and not one of them “shook”, all motion was vertical.

I done over $million of building repairs after those quakes from 2-3 story to 13 story and not one was damaged by “shaking”.

They are a vertical upheaval that radiates out from the epicenter in a wave action, all fault movement is a result of the quake and not the cause, I don't give a shit what university assholes say.