1933 Long Beach earthquake
|Date||March 10, 1933|
|Origin time||5:54 P.M. PST |
|Magnitude||6.4 Mw |
|Depth||10 km (6.2 mi) |
|Areas affected||South Coast (California)
|Total damage||$40 million |
|Max. intensity||VIII (Severe) |
|Casualties||115–120 killed |
The 1933 Long Beach earthquake took place on March 10 at 5:54 P.M. PST south of downtown Los Angeles. The epicenter was offshore, southeast of Long Beach, California, on the Newport–Inglewood Fault. The earthquake had a moment magnitude of 6.4 and a maximum Mercalli intensity of VIII (Severe). Damage to buildings was widespread throughout Southern California. An estimated forty million dollars' worth of property damage resulted, and between 115 and 120 people died. Many of these fatalities occurred as people ran out of buildings and were hit by falling debris.
The major damage occurred in the densely-populated city of Long Beach on the south-facing coast of Los Angeles County, and extended to the industrial area south of downtown Los Angeles. Unfavorable geological conditions (landfill, water-soaked alluvium) combined with poorly constructed buildings increased the damage done by the quake. In Long Beach, buildings collapsed, water tanks fell through roofs, and houses were tossed off their foundations. School buildings were among the structures that incurred the most severe damage.
The earthquake highlighted the need for earthquake-resistant design for structures in California. Many school buildings were damaged, with more than 230 school buildings that either were destroyed, suffered major damage, or were judged unsafe to occupy. The California State Legislature passed the Field Act on April 10, 1933, mandating that school buildings must be earthquake-resistant. If the earthquake had occurred during school hours, the death toll would have been much higher.
- List of earthquakes in 1933
- List of earthquakes in California
- List of earthquakes in the United States
- Stover, C. W.; Coffman, J. L. (1993), Seismicity of the United States, 1568–1989 (Revised) – U.S. Geological Survey Professional Paper 1527, United States Government Printing Office, pp. 78, 130, 131
- ISC (2015), ISC-GEM Global Instrumental Earthquake Catalogue (1900–2009), Version 2.0, International Seismological Centre
- USGS. "M6.4 - 7km WNW of Newport Beach, CA". United States Geological Survey.
- Hauksson, E.; Gross, S. (1991), "Source parameters of the 1933 Long Beach earthquake" (PDF), Bulletin of the Seismological Society of America, Seismological Society of America, 81 (1): 81
- National Geophysical Data Center / World Data Service (NGDC/WDS), Significant Earthquake Database, National Geophysical Data Center, NOAA, doi:10.7289/V5TD9V7K
- Alquist, A. E. (February 2007). "The Field Act and Public School Construction: A 2007 Perspective" (PDF). California Seismic Safety Commission. Retrieved 27 January 2011.
- USGS Historical Earthquakes - Long Beach, California – United States Geological Survey
- 75th Anniversary of the 1933 Long Beach Earthquake – California Department of Conservation
- National Information Service on Earthquake engineering page about Long Beach earthquake – National Information Service for Earthquake Engineering
- Catastrophe: A Bad One – Time
- Long Beach Earthquake: March 10, 1933 Cloyd E. Louis – Internet Archive