If the region is under active compression, these faults are
constantly rupturing, but any given valley might only experience a
large earthquake every few hundred years. Although usually only a
Magnitude 6 or 7 earthquake, it is especially deadly because the
seismic waves are highly directed, and the soft basin soil of the
valley can amplify the ground motions by over a factor of 10.
Northridge was different and is "special" in its own right. It had
the highest acceleration rate ever recorded. It was the actual 6.7
that was the culprit in that instance.
Archive powered by MHonArc 2.6.24.