Agenda - City of Santa Monica

Beach. The Kern County’s series of quakes in 1952 reached M7.7 and rank as secondlargest
in the United States since records were kept, behind San Francisco's M8.3
cataclysm of 1906. The great Alaskan shake of March 27, 1964, with a magnitude of
M8.5 was the strongest ever recorded in the nation.
The San Andreas fault is responsible for the April 18, 1906 San Francisco earthquake
and fire. This earthquake, is one of many that have resulted from episodic displacement
along the fault throughout its life of about 15-20 million years.
Santa Monica Fault
The Santa Monica fault is part of the Transverse Ranges Southern Boundary fault
system, a west-trending system of reverse, oblique-slip, and strike-slip faults that
extends for more than 200 km along the southern edge of the Transverse Ranges
(Dolan et al., 1997, 2000a). Other faults in this system are the Hollywood and Raymond
faults. The Anacapa-Dume, Malibu Coast, Santa Cruz Island, and Santa Rosa Island
faults to the west are also part of this system. (See Attachment 2 - Earthquake
Planning Scenario Map)
The Santa Monica fault extends east from the coastline in Pacific Palisades through
Santa Monica and West Los Angeles and merges with the Hollywood fault at the West
Beverly Hills Lineament in Beverly Hills, west of the crossing of Santa Monica Boulevard
and Wilshire Boulevard, where its strike is northeast. Onshore, the fault offsets the
surface 2-3.5 km south of the Santa Monica Mountains range front. 1
Vulnerability Assessment
At risk from earthquake damage are large stocks of old buildings and bridges: many
high tech and hazardous materials facilities: extensive sewer, water, and natural gas
pipelines; earth dams; petroleum pipelines; and other critical facilities and private
property located in the county. The relative or secondary earthquake hazards, which
are liquefaction, ground shaking, amplification, and earthquake-induced landslides, can
be just as devastating as the earthquake.
The California Geological Survey has identified areas most vulnerable to liquefaction.
Liquefaction occurs when ground shaking causes wet granular soils to change from a
solid state to a liquid state. This results in the loss of soil strength and the soil's ability
to support weight. Buildings and their occupants are at risk when the ground can no
longer support these buildings and structures.
Southern California has many active landslide areas, and a large earthquake could
trigger accelerated movement in these slide areas, in addition to jarring loose other
unknown areas of landslide risk.
1 Donlon, et. al., “Active Faults In the Los Angeles Metropolitan Region”, Southern California Earthquake Center,
Group C
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