large-magnitude earthquake, or its prediction, in Southern California.


B. SUMMARY

The review provided the overall assessment that the Nation is
essentially unprepared for the catastrophic earthquake (with a
probability greater than 50 percent) that must be expected in
California in the next three decades. While current response plans and
preparedness measures may be adequate for moderate earthquakes,
Federal, State, and local officials agree that preparations are
woefully inadequate to cope with the damage and casualties from a
catastrophic earthquake, and with the disruptions in communications,
social fabric, and governmental structure that may follow. Because of
the large concentration of population and industry, the impacts of
such an earthquake would surpass those of any natural disaster thus
far experienced by the Nation. Indeed, the United States has not
suffered any disaster of this magnitude on its own territory since the
Civil War.

The basis for this overall assessment is summarized below and
discussed in more detail in the subsequent chapters of this report.


C. LIKELIHOOD OF FUTURE EARTHQUAKES

Earth scientists unanimously agree on the inevitability of major
earthquakes in California. The gradual movement of the Pacific Plate
relative to the North American Plate leads to the inexorable
concentration of strain along the San Andreas and related fault