The California
Department of Transportation (Caltrans) is responsible
for the design, construction, operation and maintenance
of State Bridges and related structures for California's
transportation system. Earthquakes are prime considerations
in the design and retrofit of structures. The Office of
Earthquake Engineering is responsibilty to define the
seismic hazard for Caltrans' projects. It is the
current policy of Caltrans to utilize the anticipated
Maximum Credible Earthquake (MCE) from young faults in
and near California to define the Safety evaluation event
for design. The MCE is defined as the largest earthquake
which can be expected to occur on a fault in the current
tectonic regime.
Following the
1971 San Fernando earthquake Caltrans instituted an effort
to a develop hazard maps for California to effectively
incorporate seismic effects into the design process. This
1996 version of our hazard map is the latest map.
The map incorporates the ideas and opinions from seismologists,
geologists and other earth sciences experts .
Features
The 1996 map was developed using GIS technology ESRI's
ArcInfo (and made available through ArcView).
The length, dip, strike and depth of the fault is considered
in the development of the map. The 1996 map incorporates
273 faults in and adjacent to California. On the
map, contours of peak bedrock acceleration are presented
from 0.1 to 0.7g. The map also shows the State Highway
system and county boundaries.
Comments
& Suggestions This map is (and always
was) dynamic in nature. As new information becomes available,
it will be updated. Comments and suggestions should
be directed to:
Martha Merriam
Tel: (916) 227-7135
Email: martha_merriam@dot.ca.gov
Errata
-
A
new map is in process, please note these changes which
are NOT incorporated in the existing map. For the most
current information, contact Martha Merriam at (916)
227-7135, or martha_merriam@dot.ca.gov:
- Forest
Hill-Melones (FHM) fault is no longer used.
-
Gillis Mountain (GMT) fault is no longer used.
- Three
letter code for Southampton is STT (not SHP).
- West
Napa (WNP) fault is wrongly coded in the map as MNA.
- The
bifurcated northeastern section of the Pisgah-Bullion
fault that ruptured during the October 16, 1999 Hector
Mine earthquake in San Bernardino County is currently
under investigation by the Office of Eathquake Engineering.
- Three
letter code for the southern branch of the San Andreas
is SAS (not SAE), and its MCE moment magnitude is
7-3/4 (wrongly labelled as 6 in the map).
- Another
three letter code (SAE) with MCE moment magnitude
6 for the southern segment of central San Andreas
(SAC) is no longer used as a separate fault; it is
part of SAC with MCE moment magnitude 8.
-
For accurate locations of the Santa Maria-Foxen Canyon
(SMF) and Oceano (OCO) faults in the San Luis Obispo
region, contact John Duffy at John_D_Duffy@dot.ca.gov
-
An unnamed fault near Shasta Dam in Shasta County
is currently under investigation by the Office of
Eathquake Engineering.
- The
San Joaquin Hills fault in Orange County is currently
under investigation by the Office of Eathquake Engineering.
- The
Puente Hills Fault in Los Angeles is currently under
investigation by the Office of Earthquake Engineering
(03/15/06)
- The
Pacific Star Fault near Fort Bragg is currently under
investigation by the Office of Earthquake Engineering
(5/8/06).
Ordering
Copies of the 1996 Map: Copies of the map
(in black and white) along with the 64 page documentation
report can be obtained by contacting:
California Department of Transportation
Publications
Distribution Unit
1900 Royal Oaks Drive
Sacramento, CA 95815-3800
Please specify
that you want the California Seismic Hazard Map 1996
and include $25.00 (U.S.) for each package (map and
documentation report). The Publications Unit does not
accept purchase orders. Checks should be made out to
Caltrans . Orders may be made to Visa or MasterCard
by calling (916) 445-3520 and Pressing #2.
Disclaimer:
This map was developed solely for the use of Caltrans
to be used with their criteria and specifications. Caltrans
is not responsible for any uses made of this map outside
of Caltrans projects.
Downloads:
You can download the 1996 California Hazard Map
and the Map Report. The Map is a full color,
36 inches wide, 44 inches tall, and the size of the
file is about 2.4MB. The map is designed to be printed
on a plotter .
Note:
The IE6 browser requires the latest version of Acrobat Reader to open PDF files directly within the browser. If you do not have the latest Acrobat Reader and are using IE6, you will have to download the PDF file and open it locally on your machine.
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