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||Southern California
|Total damage||$40 million |
|Max. intensity||VIII (Severe) |
|Casualties||115 killed |
The 1933 Long Beach earthquake took place on March 10 at 5:54 P.M. PST with a moment magnitude of 6.4 and a maximum Mercalli intensity of VIII (Severe). The epicenter was offshore, southeast of Long Beach on the Newport-Inglewood Fault. Damage to buildings was widespread throughout Southern California, United States. An estimated forty million dollars' worth of property damage resulted, and 115 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 thickly settled district from Long Beach to the industrial section south of Los Angeles, where unfavorable geological conditions (landfill, water-soaked alluvium) combined with poorly constructed buildings worked to increase the damage. At 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, that the Field Act was passed by the California State Legislature on April 10, 1933. The Field Act mandated 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
- 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
- Long Beach Earthquake: 70th Anniversary – Southern California Earthquake Center
- 75th Anniversary of the 1933 Long Beach Earthquake
- National Information Service on Earthquake engineering page about Long Beach earthquake
- Catastrophe: A Bad One Time Magazine March 20, 1933
- Long Beach Earthquake: March 10, 1933 Cloyd E. Louis