6. Los Angeles/Santa Monica Fault (Magnitude 6.7 and 7.0) and
Riverside/San Bernardino/Cucamonga Fault (Magnitude 6.8)

These faults are part of a system of east-west tending faults
bordering the northern edge of the Los Angeles basin. This fault
system caused the 1971 San Fernando earthquake and is geologically
similar to the system that generated the large 1952 Kern County
earthquake. Although smaller in magnitude than the earthquakes
previously described, these postulated events are potentially quite
dangerous because of their vicinity to high population densities in
Southern California.


D. EARTHQUAKE EFFECTS

Detailed maps were prepared for each event showing qualitative
estimates of ground shaking intensity resulting from each earthquake.
These estimates are indicative of the general severity of damage to
ordinary structures. Empirical formulae providing quantitative
estimates of peak ground motion at various distances from the
postulated earthquakes were developed for use in the effects of
severe ground shaking on individual structures or critical
facilities. No estimates were made of localized effects, such as
ground failures related to liquefaction (the complete failure or loss
of strength, of a saturated soil due to shaking), landslides, and
fault rupture. These effects can be far more destructive than ground
shaking alone.

[Illustration: Figure 1. Geographic Locations of Selected Regional
Events]