1918 San Jacinto earthquake

Earthquake in Southern California May 2025 February 2025 1918 San Jacinto earthquake San Jacinto earthquake 1918.jpg The San Jacinto post office after the quake USA California California 34.05 -118.25 Los Angeles 100 left Green pog.svg California 32.72 -117.16 San Diego 100 left Green pog.svg California 33.7500 -116.8833 Bullseye1.png 40 yes 290 right 1918-04-21 22:32:29 913126 iscgem913126 1918 04 21 14:32:29 6.7 w y 10 km mi 0 on 33.7500 -116.8833 region:US_type:event inline,title San Jacinto Fault Zone $200,000 IX 1 dead, several injured The 1918 San Jacinto earthquake occurred in extreme eastern San Diego County in Southern California on April 21 at 14:32:29 local time 22:32:29 UTC. The shock had a moment magnitude of 6.7 and a maximum Mercalli intensity of IX (Violent). Several injuries and one death occurred with total losses estimated to be $200,000. Tectonic setting The San Jacinto Fault Zone is a major strike-slip fault zone that runs through San Bernardino, Riverside, San Diego, and Imperial counties in Southern California. The SJFZ is a component of the larger San Andreas transform system and is considered to be the most seismically active fault zone in the area. Together they relieve the majority of the stress between the Pacific and North American tectonic plates. Damage Many of the buildings in San Jacinto's business district were of poor construction, and all but one frame building and one concrete building collapsed, though high-quality structures did not experience serious damage. Minor damage to other buildings within 160 km us of San Jacinto also occurred. Roadways and irrigation canals also sustained damage and small sand blows were seen on a farm northwest of San Jacinto.C. W. Stover J. L. Coffman Seismicity of the United States, 1568–1989 (Revised) https://books.google.com/books?id=bY0KAQAAIAAJ U.S. Geological Survey professional paper 1527 1993 United States Government Printing Office 76, 122 The earthquake occurred on a Sunday afternoon when most of the businesses in San Jacinto were closed and void of customers. The business district had the greatest damage, though Hemet was also severely damaged. Damage to chimneys, windows, and plaster walls occurred to buildings and structures within 100 mi km of San Jacinto. Some of the damage that was inspected included landslides, partially collapsed buildings, and damaged irrigation canals and roads. Ground cracks were observed near the banks of the San Jacinto River.The San Jacinto earthquake of April 21, 1918 https://pubs.geoscienceworld.org/ssa/bssa/article-abstract/8/2-3/63/119243/The-earthquake-of-April-21-1918-in-the-San-Jacinto?redirectedFrom=fulltext S. D. Townley Sidney Dean Townley 1918 Bulletin of the Seismological Society of America Seismological Society of America VIII 2–3 45–52 10.1785/BSSA0080020045 1918BuSSA...8...45T 133342475 subscription See also List of earthquakes in 1918 List of earthquakes in California List of earthquakes in the United States References ISC-GEM Global Instrumental Earthquake Catalogue (1900–2013) http://www.isc.ac.uk/iscgem/index.php ISC 2017 International Seismological Centre Version 4.0 Significant Earthquake Database https://www.ngdc.noaa.gov/nndc/struts/form?t=101650&s=1&d=1 https://web.archive.org/web/20060929000601/http://www.ngdc.noaa.gov/nndc/struts/form?t=101650&s=1&d=1 dead September 29, 2006 National Geophysical Data Center / World Data Service (NGDC/WDS) National Geophysical Data Center, NOAA 10.7289/V5TD9V7K 1972 Data Set PAGER-CAT Earthquake Catalog https://earthquake.usgs.gov/static/lfs/data/pager/catalogs/ https://web.archive.org/web/20200313112456/ftp://hazards.cr.usgs.gov/web/data/pager/catalogs/ dead 2020-03-13 September 4, 2009 United States Geological Survey Version 2008_06.1 Sources Aftershocks of the San Jacinto earthquake of April 21, 1918 http://bssa.geoscienceworld.org/content/8/4/131 BSSA 1918 Bulletin of the Seismological Society of America Seismological Society of America 8 4 131–134 10.1785/BSSA0080040131 1918BuSSA...8..131. 239177976 subscription Paleoseismic Evidence for the 21 April 1918 Mw 6.9 Surface Rupture of the Northern Clark Strand of the Central San Jacinto Fault, California http://bssa.geoscienceworld.org/content/early/2017/02/17/0120160026 J. Barrett Salisbury T. K. Rockwell M. T. Buga 2017 Bulletin of the Seismological Society of America 107 1027–1032 1 10.1785/0120160026 2017BuSSA.107.1027B subscription External links Could a great quake strike on the enigmatic San Jacinto fault? – Temblor, Inc. 913126 Category:April 1918 in the United States Category:Earthquakes in California Category:1918 earthquakes Category:1918 in California Category:1918 natural disasters in the United States