View source for 1868 Hayward earthquake

{{short description|1868 earthquake in the San Francisco Bay Area, California, United States}}
{{Infobox earthquake
 | name        = 1868 Hayward earthquake
 | pre-1900    = yes
 | image       = 1868 Alameda County Courthouse Hayward earthquake damage.png
 | alt         = 
 | caption     = Damage to the Alameda County courthouse with inset showing building before the earthquake
 | map         = 
 | map_alt     = 
 | map_caption =
 | map2        = {{Location map+ | USA California
 |places = 
{{Location map~|California|lat=37.7|long=-122.1|mark=Bullseye1.png|marksize=40}}
{{Location map~|California|lat=38.45|long=-122.7|label=Santa Rosa|label_size=100|position=top|mark=Green pog.svg}}
{{Location map~|California|lat=36.97|long=-122.02|label=Santa Cruz|label_size=100|position=bottom|mark=Green pog.svg}}
 | relief = yes
 | width = 250
 | float = right
 | caption = }}
 | anss-url = ushis139
 | timestamp = 1868-10-21 15:53
 | local-date        = {{Start-date|October 21, 1868}}
 | local-time        = 07:53<ref name="USGS Historic Earthquakes"/>
 | duration    =
 | magnitude   = 6.3–6.7 {{M|w|link=y}}<ref name=Hough/>
 | depth       = 
 | location    = {{coord|37.7|-122.1|region:US_type:event|display=inline,title}}<ref name=Stover/>
 | fault       = [[Hayward Fault Zone]]
 | type        = [[Fault (geology)#Strike-slip faults|Strike-slip]]
 | affected    = San Francisco Bay Area <br> [[California]] <br> United States
 | damage     = $350,000 / Moderate<ref name=NGDC/>
 | intensity   = {{MMI|9}}<ref name=Stover/>
 | pga         = <!-- NN''[[Peak ground acceleration|g]]'' -->
 | tsunami     = 
 | landslide   =
 | foreshocks  =
 | aftershocks =
 | casualties  = 30<ref name=Stover/>
}}

{{multiple image
 | direction = vertical
 | image1 = Hayward earthquake 1868 damaged building 2.jpg
 | image2 = PSM V29 D327 Stud mill at haywards cal oct 21 1868.png
 | footer = Damaged building in Hayward (top) and at the Hayward [[Sawmill|stud mill]]
}}

The '''1868 Hayward earthquake''' occurred in the [[San Francisco Bay Area]], [[California]], United States on October 21. With an estimated moment magnitude of 6.3–6.7 and a maximum Mercalli intensity of IX (''Violent''), it was the most recent large [[earthquake]] to occur on the [[Hayward Fault Zone]]. It caused significant damage and a number of deaths throughout the region, and was known as the "Great San Francisco earthquake" prior to the [[1906 San Francisco earthquake|1906 San Francisco earthquake and fire]].

==Earthquake==
The earthquake occurred at 7:53&nbsp;a.m. on October 21, 1868. Its [[epicenter]] was likely located near [[Hayward, California]], and its magnitude has been estimated to have been 6.3–6.7 on the [[moment magnitude scale]]. At the surface, [[surface rupture|ground rupture]] was traced for {{convert|20|miles|sp=us}}, from [[San Leandro, California|San Leandro]] to what is now the [[Fremont, California#Warm Springs District|Warm Springs District]] in [[Fremont, California|Fremont]].<ref name="USGS Historic Earthquakes">{{cite web| url=https://earthquake.usgs.gov/regional/states/events/1868_10_21.php | title=Historic Earthquakes: Hayward, California, 1868 October 21 15:53 UTC | publisher=United States Geological Survey | year=1993 | access-date=2008-10-15| archive-url= https://web.archive.org/web/20081105233142/http://earthquake.usgs.gov/regional/states/events/1868_10_21.php| archive-date= 5 November 2008 | url-status= live}}</ref>

===Damage===
The town of Hayward experienced the most damage, with nearly every building destroyed or significantly damaged in the earthquake. The Alameda County Courthouse in San Leandro was destroyed, which resulted in the re-location of the County Seat to Oakland, its current site. The [[adobe]] chapel of [[Mission San José (California)|Mission San José]] in what is now Fremont was also destroyed, as were several buildings in San Jose, San Francisco and throughout [[Alameda County, California|Alameda County]]. Damage was reported from [[Santa Rosa, California|Santa Rosa]] in the north to [[Gilroy, California|Gilroy]] and [[Santa Cruz, California|Santa Cruz]] in the south. Thirty deaths were attributed to the earthquake.<ref name="USGS Historic Earthquakes" />

===Intensity===
The [[United States Geological Survey]] estimates that Hayward experienced shaking measuring IX (''Violent'') on the [[modified Mercalli scale]]. San Leandro experienced shaking measuring VIII (''Severe''), while [[San Francisco, California|San Francisco]] and [[Oakland, California|Oakland]] experienced shaking measuring VII (''Very strong'').<ref name="139 years and counting">{{cite video| title = The 1868 Hayward Earthquake: 139 years and counting...| medium = press conference| publisher = United States Geological Survey, Association of Bay Area Governments, Hayward Area Historical and Society Museum, Vice Mayor-City of Hayward| location = Hayward Area Historical and Society Museum| date = 17 October 2007 | url = http://1868alliance.org/activities/?id=7 | access-date= 15 October 2008 <!--DASHBot-->}}</ref>

==See also==
*[[List of earthquakes in California]]
*[[List of earthquakes in the United States]]
*[[List of historical earthquakes]]

==References==
{{reflist|refs=
<ref name=Hough>{{citation|title=The 1868 Hayward Fault, California, Earthquake: Implications for Earthquake Scaling Relations on Partially Creeping Faults|url=http://bssa.geoscienceworld.org/content/105/6/2894.abstract|first1=S. E.|last1=Hough|author-link=Susan Hough|first2=S. S.|last2=Martin|year=2015|journal=Bulletin of the Seismological Society of America|volume=105|number=6|pages=2984, 2907|doi=10.1785/0120140372|bibcode=2015BuSSA.105.2894H}}</ref>
<ref name=NGDC>{{citation|title=Significant Earthquake Information|url=https://www.ngdc.noaa.gov/hazel/view/hazards/earthquake/event-more-info/2148|author=National Geophysical Data Center / World Data Service (NGDC/WDS)|work = NCEI/WDS Global Significant Earthquake Database|publisher=[[National Geophysical Data Center]], [[National Oceanic and Atmospheric Administration|NOAA]]|doi=10.7289/V5TD9V7K|year=1972|type=Data Set}}</ref>
<ref name=Stover>{{cite book|last1=Stover|first1=C.W.|last2=Coffman|first2=J.L.|title=Seismicity of the United States, 1568–1989 (Revised)|url=https://books.google.com/books?id=bY0KAQAAIAAJ|series=U.S. Geological Survey professional paper 1527|year=1993|publisher=[[United States Government Printing Office]]|pages=73, 104}}</ref>}}

==Further reading==
* {{citation|title=The "Report" of the 1868 Haywards earthquake|url=http://www.bssaonline.org/content/76/1/71.abstract|first1=M. L.|last1=Aldrich|first2=B. A.|last2=Bolt|author-link2=Bruce Bolt|first3=A. E.|last3=Leviton|first4=P. U.|last4=Rodda|year=1986|journal=Bulletin of the Seismological Society of America|volume=76|number=1|pages=71–76|doi=10.1785/BSSA0760010071 |bibcode=1986BuSSA..76...71A |access-date=2014-07-22|archive-date=2015-09-23|archive-url=https://web.archive.org/web/20150923194932/http://www.bssaonline.org/content/76/1/71.abstract|url-status=dead}}
* {{citation|title=Modified Mercalli Intensity Maps for the 1868 Hayward Earthquake Plotted in ShakeMap Format|url=http://pubs.usgs.gov/of/2008/1121/index.html|first1=J.|last1=Boatwright|first2=H.|last2=Bundock|series=Open-File Report 2008-1121|publisher=United States Geological Survey}}

==External links==
*[http://1868alliance.org/ 1868 Hayward Earthquake Alliance]
*[http://www.oac.cdlib.org/findaid/ark:/13030/tf5z09p42w/ Images from the 1868 earthquake aftermath] – [[The Bancroft Library]]
*[http://sflib1.sfpl.org:82/search/d?SEARCH=Earthquakes+1868 Photos of damage in San Francisco following the 1868 earthquake] – [[San Francisco Public Library]]
*[http://news.stanford.edu/pr/96/960711haywfault.html Prepare for big ruptures on Hayward fault, scientists say] – [[Stanford University]]
*[https://www.youtube.com/watch?v=D6bmBq-mUUA&t=1623s The 150th Anniversary of the Damaging 1868 Hayward Earthquake: Why It Matters and How We Can Prepare for Its Repeat] – Tom Brocher (USGS)

{{Earthquakes in 1868}}
{{Earthquakes in California}}
{{Earthquakes in the United States}}
{{Hayward, California}}

[[Category:Earthquakes in California|1868]]
[[Category:1868 earthquakes|Hayward earthquake]]
[[Category:History of the San Francisco Bay Area]]
[[Category:1868 in California|Hayward earthquake]]
[[Category:History of Hayward, California]]
[[Category:October 1868 events]]
[[Category:1868 natural disasters in the United States]]