Download California earthquakes: 1933

California Earthquakes
Through an historical perspective
San
Francisco
Loma Prieta
San Fernando
Northridge
Long Beach
1933 Long Beach Earthquake
• March 10,1933, 5:54 PM
• Mw = 6.4
• Right lateral slip along Newport-Inglewood
Fault
• No surface rupture
• 120 fatalities
• 50 million dollars in damage
NewportInglewood
Fault
Franklin Junior High School
120 schools destoyed; 70 damaged
Collapse of unreinforced masonry
structures
Pile of Bricks
Collapse of Unreinforced Masonry School
• 5 teachers killed
• Field Act passed
• Gave the state authority to supervise
structures built for schools
1971 San Fernando Earthquake
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February 9, 1971, 6:01 AM
Thrust fault dipping to the north
12 miles of surface rupture
Maximum displacement of 6 feet
65 fatalities
500 million dollars of damage
Location, San Fernando Valley
San Fernando Valley
Earthquakes
• Cross-sections of
the San Fernando
and Northridge
earthquakes.
Dam: end terminus of the Los Angeles
water system; 80 % of LA’s water
Shaking caused landslide
80,000 people below
House over Garage
Veterans Hospital
Olive-View Hospital
(soft story collapse)
1989 Loma Prieta Earthquake
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October 17, 1989; 5:04 PM
Mw = 6.9
Oblique movement on the San Andreas Fault
Maximum offset of 3-4 feet
~ 25 miles of fault plane movement
15 seconds of shaking
6-10 billion dollars of damage
Earth
Materials
The Northridge Earthquake
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January 17. 1994, 4:31 am
Epicenter: 1 mile SW of Northridge
Magnitude: Mw 6.7
Type of fault: blind thrust, the Pico Thrust
Hypocenter: 18.4 km
Deaths: 57
1500 seriously injured
Cost: 15 billion dollars
Northridge Earthquake
The mountains are the surface expression of the fault.
This fault was unknown before this earthquake.
Collapse of Soft Story
Failure of Reinforced Concrete Structures
Rebuilt Olive-view Hospital
Success of
retrofitted URM
structures
Change in how earthquake
insurance is distributed.