TIME February 9, 1971 / 6:01 am PST
LOCATION 34° 24.67' N, 118° 24.04' W
MAGNITUDE MW 6.6
DEPTH: 8.4 km
TYPE OF FAULTING thrust
FAULT INVOLVED San Fernando fault zone; minor offset reported on the eastern Santa Susana fault zone
Also known as the Sylmar Earthquake, this earthquake occurred
on the San Fernando fault zone, a zone
of thrust faulting which broke the surface in the Sylmar-San Fernando Area.
The total surface rupture was roughly 19 km (12 miles) long.
The maximum slip was up to 2 meters (6 feet).
The earthquake caused over $500 million in property damage and 65 deaths.
Most of the deaths occurred when the Veteran's Administration Hospital
collapsed. Several other hospitals, including the Olive View
Community Hospital in Sylmar (pictured below)
suffered severe damage. Newly constructured freeway
overpasses also collapsed, in damage scenes similar to those
which occurred 23 years later in the 1994
Northridge Earthquake. Loss of life could have been much
greater had the earthquake struck at a busier time of day.
In response to this earthquake, building codes were strengthened and the
Alquist Priolo Special Studies Zone Act was passed in 1972.
The purpose of this act is to prohibit the location of most structures
for human occupancy across the traces of active faults and to
mitigate thereby the hazard of fault rupture.
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