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{{Short description|Earthquakes in California and Baja California}}
{{Infobox earthquake
| name = 1987 Superstition Hills earthquakes
| affected = [[California]] and [[Mexico]]
| intensity = {{MMI|6}}<br><br>{{MMI|7}}
| pga = 
| pgv = 
| tsunami = 
| landslide = 
| foreshocks = 
| damages = {{US$|3}}{{nbsp}}million
| aftershocks = 
| citations = 
| anss-url-A = ci628016
| depth-A = {{cvt|7.5|km}}
| timestamp-A = 1987-11-24 13:15:56
| magnitude-A = 6.5 {{M|w|link=yes}}
| local-date-A = November 24, 1987
| local-time-A = 05:15 PST
| casualties = 2 dead, 94 injured
| type = Strike-slip
| timestamp = 1987-11-24 01:54:14
| fault = 
| alt = 1987 Superstition Hills earthquake
| caption = 
| map = 
| map_alt = 
| map_caption = 
| location = {{coord|33.090|-115.792|region:US|display=inline, title}}
| image = 
| map2 = {{Location map+ | USA California
|places =
{{Location map~|California|lat=34.05|long=-118.25|label=Los Angeles|label_size=100|mark=Green pog.svg}}
{{Location map~|California|lat=36.18|long=-115.14|label=Las Vegas|label_size=100|position=top|mark=Green pog.svg}}
{{Location map~|California|lat=32.72|long=-117.16|label=San Diego|label_size=100|position=top|mark=Green pog.svg}}
{{Location map~|California|lat=33.015|long=-115.852|mark=Bullseye1.png|marksize=40}}
| width = 260
| float = right
| caption =
| relief = yes
}}
| isc-event = 453653
| anss-url = ci134894
| local-date = November 23, 1987
| local-time = 17:54 PST
| duration = 
| magnitude = 6.0 {{M|w|link=yes}}
| depth = {{cvt|2.3|km}}
| isc-event-A = 453722
}}

The '''1987 Superstition Hills earthquake''' affected the [[Imperial Valley]] of [[California]] and [[Baja California]] on November 24, nearly 12 hours after a {{M|w|link=y}} 6.0 [[foreshock]], called the '''Elmore Ranch earthquake'''. The mainshock, measuring {{M|w|link=y}} 6.5, struck at 17:54 PST, along the Superstition Hills segment of the San Jacinto Fault Zone. The earthquake generated a {{cvt|27|km}} surface rupture with additional postseismic slip continuing for a year.

The earthquake caused damage amounting to {{US$|3}}{{nbsp}}million. Damage was considerable in Mexicali, were two people were killed and 50 people sustained injuries. Another 44 people were injured in the Imperial Valley. Buildings El Centro, Imperial, and Westmorland sustained collapsed chimneys, ruptured pipes and shattered windows. The rebuilt Imperial County services building, which replaced an originally five-story structure, remained structurally intact. Damage to canal infrastructure cost over {{US$|600}}{{nbsp}}thousand.

== Geology ==
The [[Imperial Valley]] is a seismically active area in [[California]] where the [[San Andreas Fault]] and [[San Jacinto Fault Zone]] (SJFZ) discontinues. This region represents a transition zone between continental [[transform fault]]ing and oceanic [[rift]]ing in the [[Gulf of California]]. South of the San Andreas Fault and between the [[Imperial Fault Zone|Imperial Fault]] is the [[Brawley seismic zone]]—the northernmost ridge feature in the [[Leaky transform fault|ridge–transform boundary]]. Faults in the Brawley Seismic Zone typically trend northeast, perpendicular to the plate boundary faults. Labeled "cross-faults", these are oriented perpendicular to the direction of rifting and were previously interpreted to be normal faults. However, recent seismic activity show that these faults produce left-lateral strike-slip motion.<ref name="Hudnut89b">{{cite journal |last1=Hudnut |first1=K.W. |last2=Seeber |first2=L. |last3=Rockwell |first3=T.K. |last4=Goodmacher |first4=J. |last5=Klinger |first5=R. |last6=Lindvall |first6=S. |last7=McElwain |first7=R. |title=Surface ruptures on cross-faults in the 24 November 1987 Superstition Hills, California, earthquake sequence |date=1989 |journal=[[Bulletin of the Seismological Society of America]] |volume=79 |issue=2 |pages=282–296 |doi=10.1785/BSSA0790020282 |doi-broken-date=1 November 2024 |url=https://core.ac.uk/download/pdf/216196719.pdf |access-date=2024-10-09 |archive-date=2024-10-10 |archive-url=https://web.archive.org/web/20241010070005/https://core.ac.uk/download/pdf/216196719.pdf |url-status=live }}</ref>

The SJFZ is a {{cvt|244|km}}-long right-lateral structure that runs parallel to the San Andreas Fault.<ref name="Singer98">{{citation|last=Singer|first=Eugene|title=Geology of California's Imperial Valley: A Monograph by Eugene Singer |url=http://www.sci.sdsu.edu/salton/San%20AndreasFaultSyst.html|date=1998|access-date=13 December 2020|archive-url=https://web.archive.org/web/20110324080539/http://www.sci.sdsu.edu/salton/San%20AndreasFaultSyst.html|archive-date=24 March 2011}}</ref> The SJFZ is southern California's most seismically active fault zone. It was responsible for a large surface-rupturing [[1968 Borrego Mountain earthquake|earthquake in 1968]]. The fault zone is highly segmented, consisting of seven individually named segments.<ref name="Dorsey02">{{Cite book|last=Dorsey|first=Rebecca J.|chapter=Stratigraphic record of Pleistocene initiation and slip on the Coyote Creek fault, lower Coyote Creek, southern California|title=Contributions to Crustal Evolution of the Southwestern United States|url=https://pages.uoregon.edu/rdorsey/sanjacinto.html|date=2002|publisher=Geological Society of America|doi=10.1130/0-8137-2365-5.251|volume=365|isbn=9780813723655|pages=251–269|access-date=2022-08-25|archive-date=2022-10-14|archive-url=https://web.archive.org/web/20221014225017/https://pages.uoregon.edu/rdorsey/sanjacinto.html|url-status=live}}</ref> Although part of one fault system, these segments are assigned names such as the Coyote Creek, Superstition Hills, and Superstition Mountain faults. The Superstition Hills Fault (SHF) is a vertically dipping, {{cvt|38|km}}-long section.<ref name="Treiman99">{{cite web |last1=Treiman |first1=J.A. |last2=Lundberg |first2=M. |last3=compilers |title=Fault number 125d, San Jacinto fault, Superstition Hills section, in Quaternary fault and fold database of the United States |url=https://earthquake.usgs.gov/cfusion/qfault/show_report_AB_archive.cfm?fault_id=125&section_id=f |publisher=United States Geological Survey |access-date=19 August 2022 |date=1999 |archive-date=25 August 2022 |archive-url=https://web.archive.org/web/20220825105304/https://earthquake.usgs.gov/cfusion/qfault/show_report_AB_archive.cfm?fault_id=125&section_id=f |url-status=live }}</ref> In 1956, it produced a small surface rupture during a {{M|l|link=y}} 5.6 earthquake. [[aseismic creep|Triggered slip]] also occurred during earthquakes in 1968 and [[1979 Imperial Valley earthquake|1979]].<ref name="Magistrale89" /> The SHF was not known to be capable of produing large earthquakes prior to 1987 although it may have been the source of earthquakes in 1906 and [[1915 Imperial Valley earthquakes|1915]]. However, other faults were also candidates for producing these earthquakes.<ref name="Hudnut4">{{cite journal |last1=Hudnut |first1=K. W. |last2=Sieh |first2=K. E. |title=Behavior of the Superstition Hills fault during the past 330 years |journal=79 |date=1989 |issue=2 |pages=304–329 |doi=10.1785/BSSA0790020304 |doi-broken-date=2024-11-02 |url=https://authors.library.caltech.edu/records/kx5md-87h87 |access-date=2024-10-08 |archive-date=2024-10-08 |archive-url=https://web.archive.org/web/20241008124221/https://authors.library.caltech.edu/records/kx5md-87h87 |url-status=live }}</ref>

== Earthquakes ==
===Elmore Ranch earthquake===
The {{M|w}} 6.0 foreshock struck at a depth of {{cvt|2.3|km}}, at 17:54 PST.<ref name="iscA">{{ Cite isc | OB | 453653 | mode=cs2 | title= On-line Bulletin | url= http://www.isc.ac.uk/cgi-bin/FormatBibprint.pl?evid=453653}}</ref> The epicenter was located in a sparsely populated area {{cvt|22.5|km}} southwest of [[Westmorland, California|Westmorland]].<ref name="GC">{{Cite journal|year=1988|first=Angela |last= Blanchette|title=Earthquakes Strike Imperial Valley in "Superstition Hills Sequence"|url=http://www.johnmartin.com/earthquakes/eqpapers/00000073.htm|journal=California Geology|volume=41|issue=2|archive-url=https://web.archive.org/web/20040317013833/https://www.johnmartin.com/earthquakes/eqpapers/00000073.htm|archive-date=17 March 2004}}</ref> It occurred on a previously unmapped fault, later called the Elmore Ranch Fault Zone (ERFZ).<ref name="Magistrale89">{{Cite journal |last1=Magistrale |first1=Harold |last2=Jones |first2=Lucile |last3=Kanamori |first3=Hiroo |author-link3=Hiroo Kanamori |date=April 1989 |title=The Superstition Hills, California, earthquakes of 24 November 1987 |url=https://authors.library.caltech.edu/records/q5jy8-1xh81 |journal=Bulletin of the Seismological Society of America |volume=79 |issue=2 |pages=239–251 |issn=0037-1106 |doi=10.1785/BSSA0790020239 |bibcode=1989BuSSA..79..239M |access-date=9 October 2024 |archive-date=27 July 2024 |archive-url=https://web.archive.org/web/20240727222257/https://authors.library.caltech.edu/records/q5jy8-1xh81 |url-status=live }}</ref> This event was associated with aftershocks that implied rupture occurred along a northeast striking fault based on its distributions. The rupture propagated bilaterally for {{cvt|20–25|km}}; northeast towards the Brawley Seismic Zone and southwest, where it joined the SHF. The surface rupture was only observed for half the rupture length. It was associated with left-lateral slip and had a maximum offset of nearly {{cvt|20|cm}}. Between {{cvt|2.8|cm}} and {{cvt|4.8|cm}} of slip was measured on the Lone Tree, Kane Springs, and Eastern Kane Springs segments of the ERFZ. The main ERFZ strand had a measured displacement of {{cvt|13|cm}}.<ref name="Hudnut89b" />

===Superstition Hills earthquake===
About 12 hours later, a {{M|w}} 6.5 occurred at {{cvt|7.5|km}} depth<ref name="iscB">{{ Cite isc | OB | 453722 | mode=cs2 | title= On-line Bulletin | url= http://www.isc.ac.uk/cgi-bin/FormatBibprint.pl?evid=453722 }}</ref> with an epicenter at the northwestern termination of the SHF, where it intersects the ERFZ. It was followed by an aftershock zone roughly parallel to the SHF formed, although situated several kilometers southwest of the main rupture trace.<ref name="Hudnut89b" /> The shock also produced a {{cvt|27|km}} surface rupture running southeastward from the epicenter.<ref name="Sharpetal89" /><ref name="Hudnut89a">{{cite journal |url=https://igppweb.ucsd.edu/~dkilb/NG/SaltonSea/Publications_files/Hudnut-etal_GL016i002p00199.pdf |last1=Hudnut |first1=K.W. |last2=Seeber |first2=L. |last3=Pacheco |first3=J. |title=Cross-fault triggering in the November 1987 Superstition Hills Earthquake Sequence, southern California |journal=Geophysical Research Letters |date=1989 |volume=16 |issue=2 |pages=199–202 |doi=10.1029/GL016i002p00199 |bibcode=1989GeoRL..16..199H |access-date=2024-10-08 |archive-date=2024-10-10 |archive-url=https://web.archive.org/web/20241010070005/https://igppweb.ucsd.edu/~dkilb/NG/SaltonSea/Publications_files/Hudnut-etal_GL016i002p00199.pdf |url-status=live }}</ref> Right-lateral offsets were observed along two sections of the SHF and on {{cvt|4|km}} of the Wienert Fault.<ref name="Sharpetal89">{{cite journal |last1=Sharp |first1=R. V. |last2=Budding |first2=K. E. |last3=Boatwright |first3=J. |last4=Ader |first4=M. J. |last5=Bonilla |first5=M. G. |last6=Clark |first6=M. M. |last7=Fumal |first7=T. E. |last8=Harms |first8=K. K. |last9=Lienkaemper |first9=J. J. |last10=Morton |first10=D. M. |last11=O'Neill |first11=B. J. |last12=Ostergren |first12=C. L. |last13=Ponti |first13=D. J. |last14=Rymer |first14=M. J. |last15=Saxton |first15=J. L. |last16=Sims |first16=J. D. |title=Surface faulting along the Superstition Hills fault zone and nearby faults associated with the earthquakes of 24 November 1987 |journal=Bulletin of the Seismological Society of America |date=1989 |volume=79 |issue=2 |pages=252–281 |doi=10.1785/BSSA0790020252|bibcode=1989BuSSA..79..252S }}</ref>

Over the next 339 days, the SHF continued to produce [[Aseismic creep|aseismic slip]], increasing the ground displacements.<ref name="Stover and Coffman" /> By August 1988, up to {{cvt|80.2|cm}} of offset was measured along the SHF, with much of the slip occurring within the first five days of the mainshock.<ref name="McGill89">{{cite journal |last1=McGill |first1=Sally F. |last2=Allen |first2=Clarence R. |last3=Hudnut |first3=Kenneth W. |last4=Johnson |first4=David C. |last5=Miller |first5=Wayne F. |last6=Sieh |first6=Kerry E. |title=Slip on the Superstition Hills fault and on nearby faults associated with the 24 November 1987 Elmore Ranch and Superstition Hills earthquakes, southern California |journal=Bulletin of the Seismological Society of America |date=1989 |volume=79 |issue=2 |pages=362–375 |doi=10.1785/BSSA0790020362 |url=https://s3.us-west-2.amazonaws.com/caltechauthors/ea/9b/ce04-9e7c-4896-aa91-c332b04bcb70/data?response-content-type=application%2Foctet-stream&response-content-disposition=attachment%3B%20filename%3D362.full.pdf&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIARCVIVNNAKP37N3MU%2F20231203%2Fus-west-2%2Fs3%2Faws4_request&X-Amz-Date=20231203T060500Z&X-Amz-Expires=60&X-Amz-SignedHeaders=host&X-Amz-Signature=7afaa871ddd11b3334082450756b34b35d86d97491384c679ba304c4e687c6ab |archive-url=https://web.archive.org/web/20231203060500/https://s3.us-west-2.amazonaws.com/caltechauthors/ea/9b/ce04-9e7c-4896-aa91-c332b04bcb70/data?response-content-type=application%2Foctet-stream&response-content-disposition=attachment%3B%20filename%3D362.full.pdf&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIARCVIVNNAKP37N3MU%2F20231203%2Fus-west-2%2Fs3%2Faws4_request&X-Amz-Date=20231203T060500Z&X-Amz-Expires=60&X-Amz-SignedHeaders=host&X-Amz-Signature=7afaa871ddd11b3334082450756b34b35d86d97491384c679ba304c4e687c6ab|archive-date=3 December 2023}}</ref> At at the time of observation in 1988, the Wienert Fault's southern portion produced vertical offsets of {{cvt|25|cm}} and was actively increasing.<ref name="Sharpetal89" />

The mainshock also [[Aseismic creep|triggered slip]] on the central section of the Coyote Creek Fault, north of the SHF. The {{cvt|3|km}} rupture comprised two semi-continuous segments. It had a maximum right-lateral slip of {{cvt|1.5|cm}}, and minor vertical offsets were also recorded. Installed [[creepmeter]]s indicated several millimeters of slip occurred on the San Andreas Fault, but was insufficient to create a surface rupture.<ref name="Hudnut89c" /> One of these instrument recorded {{cvt|0.69–0.76|cm}} of slip.<ref name="McGill89" /> Triggered slip was also measured on the Imperial Fault.<ref name="Hudnut89c">{{cite journal |last1=Hudnut |first1=K. W. |last2=Clark |first2=M. M. |title=New slip along parts of the 1968 Coyote Creek fault rupture, California |journal=[[Bulletin of the Seismological Society of America]] |date=1989 |volume=79 |issue=2 |pages=451–465 |doi=10.1785/BSSA0790020451 |doi-broken-date=1 November 2024 |url=https://www.researchgate.net/publication/279681818}}</ref> Movements on these faults may have initiated less than three minutes after the two large earthquakes. The Imperial Fault also produced motion about three hours following the mainshock.<ref name="McGill89" />

===Ground motion===
{{main|Strong ground motion}}
[[File:USGS Shakemap - 1987 Superstition Hills earthquake.jpg|thumb|A USGS [[ShakeMap]] for the November 24 mainshock]]
Strong motion network was established by the [[United States Coast and Geodetic Survey]] in 1932 to record strong-motion data across the western United States. In the Imperial Valley, it involved installating an [[accelerograph]] at El Centro which would record important data for the earthquakes of [[1940 El Centro earthquake|1940]] and 1987. By 1979, the network expanded to 30 stations in the valley, and nearly 700 strong motion accelerograms were gathered from earthquakes by 1987.<ref name="Porcella87" />

The 1987 events produced 65 recordings from 40 stations across the valley. Horizontal [[peak ground acceleration]]s (pga) during the foreshock exceeded 0.1 ''[[Spectral acceleration|g]]'' at six stations. The nearest station at Superstition Mountain was {{cvt|13|km}} away; recording a pga of 0.13 ''g''. The highest pga was 0.22 ''g'', measured at [[Calipatria, California|Calipatria]], {{cvt|26|km}} away.<ref name="Porcella87">{{citation |last1=Porcella |first1=R.L. |last2=Etheredge |first2=E. |last3=Maley |first3=R. |last4=Switzer |first4=J. |title=Strong-motion data from the Superstition Hills earthquakes of 0154 and 1315 [GMT], November 24, 1987 |date=1987 |series=Open-File Report 87-672 |pages=2–6 |url=https://pubs.usgs.gov/of/1987/0672/report.pdf |publisher=United States Geological Survey |access-date=August 25, 2022 |archive-date=August 25, 2022 |archive-url=https://web.archive.org/web/20220825171206/https://pubs.usgs.gov/of/1987/0672/report.pdf |url-status=live }}</ref>

Twenty-five stations recorded a maximum horizontal pga exceeding 0.1 ''g'' within {{cvt|60|km}} of the mainshock's epicenter. These stations recorded a pga of at least 0.3 ''g''. The pga at the Superstition Mountain station was the largest and longest ever observed in its 55-year records; 0.9 ''g'' and 0.7 ''g'' in the horizontal and 0.6 ''g'' in the vertical directions.<ref name="Porcella87" /> The site also recorded 16 seconds of intense ground motion.<ref name="eeri1">{{cite web |title=Superstition Hills Earthquakes–November 23 and 24, 1987 Imperial County, California |url=https://www.eeri.org/images/archived/wp-content/uploads/USA_CA_SuperstitionHills_Insert_Feb88.pdf |publisher=Earthquake Engineering Research Institute |access-date=8 October 2024 |date=1988 |archive-date=8 October 2024 |archive-url=https://web.archive.org/web/20241008014346/https://www.eeri.org/images/archived/wp-content/uploads/USA_CA_SuperstitionHills_Insert_Feb88.pdf |url-status=live }}</ref>

Damage from the foreshock in Calipatria, El Centro, Heber and Westmorland corresponded to VI (''Strong'') on the [[Modified Mercalli intensity scale]] (MMI).<ref name="anss1">{{Cite anss|California|1987|ci134894|title=M 6.2 – 17&nbsp;km WNW of Westmorland, CA}}</ref> The mainshock had a maximum MMI of VI–VII (''Strong''–''Very strong'') at El Centro and Westmorland. Intensity VI was felt at Brawley, Calexico, Calipatria, Heber, Holtville, Imperial and Seeley. It was widely felt across southern California. Shaking was also felt over {{cvt|300|km}} away in [[Las Vegas]], [[Nevada]] and [[Tempe, Arizona]], and over {{cvt|100|km}} away in Mexico's Tijuana and Ensenada.<ref name="Stover and Coffman" /><ref name="anss2">{{Cite anss|California|1987|ci628016|title=M 6.6 – 22&nbsp;km W of Westmorland, CA}}</ref>

==Impact==
Although both earthquakes were larger than the [[Whittier Narrows earthquake]] of October, damage was moderate due to their location in the sparsely populated valley,<ref name="Feldman1" /> estimated at {{US$|3}}{{nbsp}}million.<ref name="Stover and Coffman" /> At least 94 people were injured; 50 in Mexicali and 44 in Imperial County. In Mexicali, a two people died after an oncoming vehicle crashed into them while evacuating a factory. Some people had broken bones, sprains, cuts and some heart attacks. Thirty-five buildings were damaged including three hospitals and the city hall. Some 650 people were evacuated from these buildings. An [[Immigration and Naturalization Service]] station between the city and Calexico experienced heavy interior damage.<ref name="Reich1" /> Fires also broke out in other buildings.<ref name="Armstrong87">{{Cite news|date=25 November 1987|title=California gets more reminders of quake potential. Experts say temblors that hit the lower Imperial Valley and Mexicali, Mexico don't mean more are likely to follow soon.|access-date=26 August 2022|first=Scott|last=Armstrong|url=https://www.csmonitor.com/1987/1125/aquake.html|work=[[The Christian Science Monitor]]|archive-date=26 August 2022|archive-url=https://web.archive.org/web/20220826051346/https://www.csmonitor.com/1987/1125/aquake.html|url-status=live}}</ref>

The large foreshock cut power in some parts of [[Niland, California|Niland]], but the town was undamaged. In a Westmorland grocery store, merchandaise fell and a window cracked. Damage to telephone lines temporarily disrupted communication services in the valley. At the [[San Onofre Nuclear Plant]], there was an "unusual event" declaration. A runway at the [[Naval Air Facility El Centro]] was closed for inspections, which later revealed small cracks.<ref name="Feldman1">{{Cite news |last1=Feldman |first1=Paul |last2=Reza |first2=H.G. |date=24 November 1987 |title=Imperial Valley Rocked by 6.2 Quake; Damage Minor |work=Los Angeles Times |url=https://www.latimes.com/archives/la-xpm-1987-11-24-mn-24277-story.html |access-date=November 21, 2020 |archive-date=2020-11-29 |archive-url=https://web.archive.org/web/20201129091334/https://www.latimes.com/archives/la-xpm-1987-11-24-mn-24277-story.html |url-status=live }}</ref><ref name="Reich1" />

Collapsed chimneys, severed pipes, shattered windows, and highways were offset in the towns of El Centro, Imperial, and Westmorland. Liquefaction damage rendered a bridge across the [[New River (Mexico–United States)|New River]] a complete loss. Near Westmorland, operations at the Desert Test Range Control Center ceased due to damaged a damaged water tank and equipment.<ref name="Stover and Coffman" /> Several buildings in [[Calexico, California|Calexico]]'s business district sustained damage, and a brick wall toppled onto some cars.<ref name="Reich1" /> The two-story Imperial County services building, a steel frame structure, only received nonstructural damage. County buildings in El Centro were structurally resilient but had material debris.<ref name="eeri1" /> The [[All-American Canal|Southern California Irrigation District]] estimated the damage to its facilities at {{US$|600–750}}{{nbsp}}thousand. The foreshock caused minor buckling of the canal's concrete reinforce while the mainshock collapsed many of the concrete.<ref name="Stover and Coffman">{{cite book |first1=Carl W. |last1=Stover |first2=Jerry L. |last2=Coffman |title=Seismicity of the United States, 1568-1989 (Revised) |series=Professional Paper |date=1993 |publisher=U.S. Geological Survey Professional Paper |location=United States Government Printing Office, Washington |edition=1527 |doi=10.3133/pp1527 |url=https://pubs.er.usgs.gov/publication/pp1527 |access-date=2022-08-25 |archive-date=2022-08-06 |archive-url=https://web.archive.org/web/20220806033204/http://pubs.er.usgs.gov/publication/pp1527 |url-status=live }}</ref> Concrete channels and pipe siphons had significant damage. Cracking was also extensive along the aqueduct.<ref name="eeri1" />

==Response==
The mainshock immediately disrupted power to 65,000 homes and businesses, but it was restored within 20 minutes. Telecommunications, power and gas services were interrupted throughout Westmorland, El Centro, Calexico and Mexicali. Despite the damage to canal facilities, officials said it did not affect the flow of water. In El Centro, detainees of the Immigration and Naturalization Service were relocated to the courtyard due to damage at the station. Law enforcement officers were on high alert for looters in Calexico. [[California State Route 86|California 86]] between Westmorland and El Centro was damaged and closed off. A buckled road near the junction with [[Interstate 8]] also forced [[California State Route 98|California 98]] to close. Aircraft from the [[United States Customs Service]] and Mexico were flown to inspect the damage.<ref name="Reich1" />

In [[Orange County, California|Orange County]], residents stocked up on their [[earthquake preparedness]] kits. One store also saw a rise in sales for bottled water, water purification devices and propane tanks. In [[La Habra, California|La Habra]], four households called for a home inspection. The [[California Department of Transportation]] dispatched 150 personnel to inspect freeways in the county for damage. The [[San Diego Fire-Rescue Department]] reported small cracks in the walls and ceilings at five stations.<ref name="Reich1">{{Cite news|last1=Reich|first1=Kenneth|first2=H. G.|last2=Reza|date=25 November 1987|title=6.3 Quake Injures 94 Along Mexican Border: Imperial Valley Temblor, 2nd in 12 Hours, Damages Buildings in Mexicali, El Centro|work=Los Angeles Times|url=https://www.latimes.com/archives/la-xpm-1987-11-25-mn-16099-story.html|access-date=2024-10-08|archive-date=2024-10-08|archive-url=https://web.archive.org/web/20241008101945/https://www.latimes.com/archives/la-xpm-1987-11-25-mn-16099-story.html|url-status=live}}</ref>

== See also ==
{{Portal|California}}
* [[List of earthquakes in the United States]]
* [[List of earthquakes in California]]
* [[List of earthquakes in Mexico]]

== References ==
{{reflist}}

==External links==
* {{EQ-isc-link|453653}}
* {{EQ-isc-link|453722}}

{{Earthquakes in 1987}}
{{Earthquakes in California}}
{{Earthquakes in the United States}}
{{earthquakes in Mexico}}
{{Imperial County, California}}

[[Category:1987 earthquakes|Superstition Hills earthquakes]]
[[Category:November 1987 events in the United States|Superstition Hills earthquakes]]
[[Category:November 1987 events in Mexico|Superstition Hills earthquakes]]
[[Category:Earthquakes in California]]
[[Category:Earthquakes in Mexico]]
[[Category:History of Imperial County, California]]
[[Category:Imperial Valley]]
[[Category:1987 in Mexico|Superstition Hills earthquakes]]
[[Category:1987 in California|Superstition Hills earthquakes]]
[[Category:1987 natural disasters in the United States|Superstition Hills earthquakes]]
[[Category:Disasters in California]]
[[Category:Disasters in Mexico]]
[[Category:Doublet earthquakes]]
[[Category:Geology of Imperial County, California]]
[[Category:1987 disasters in North America|Superstition Hills earthquakes]]

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