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Seismic Shaking
Hazard Maps of California
Seismic shaking maps are prepared
using consensus information on
historical earthquakes, faults, and
geologic materials.
Historic
earthquakes, areas damaged, the
slip
rates of major faults, and
geologic
materials were combined to calculate
the shaking hazard at peak ground
acceleration, spectral acceleration
for 0.3-second period, and
spectral
acceleration for 1.0-second period.
The shaking hazard maps show the
level of ground motion that has 1
chance in 475 of being exceeded each
year, which is equal to a 10%
probability of being exceeded in 50
years.
These levels of ground shaking are
used primarily for formulating
building codes and for designing
buildings. The maps can also be used
for estimating potential economic
losses and preparing for emergency
response. The shaking hazard maps do
not include hazards from ground
deformation such as liquefaction,
landslides, or surface fault
ruptures. These maps are not
intended for site-specific hazard
analysis, but only provide a
regional perspective of earthquake
hazard in California. Information
used in preparing the maps was
developed in cooperation with the U.
S. Geological Survey.
CGS
has published a poster
depicting the various seismic hazard
maps and input information that are
shown below. This poster was published as
California Dept. of Conservation -
California Geological Survey Map
Sheet 48 (1999). The cost of the
map sheet is $12.00 folded and $15.00 flat,
plus $4.00 shipping and handling.
You can order a copy by contacting
our publications group at: (916)
445-5716 or
clicking here.
Click on the image below to obtain a
more detailed version of the map.
Spectral Acceleration for 0.3-second
period
Spectral Acceleration for 0.1-second
period
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