Answer:
One thing they COULD do is have the St.Louis and Houston Stations both send out very high wave frequencies and figure out from there what the magnitude is and send it back to LA, but that might take a bit of time, depening on if power cables aren't down.
It occurs more quickly because the chemicals work better at a specific/optimum temperature that the hotter climates have. whereas in a colder climate the chemicals could have been killed off before they start the weathering process.