View source for 1976 Guatemala earthquake

{{Short description|February 1976 earthquake in Guatemala}}
{{Infobox earthquake
| title = 1976 Guatemala earthquake
| timestamp = 1976-02-04 09:01:46
| isc-event = 717474
| anss-url  = iscgem717474
| local-date  = {{Start date|1976|02|04}}
| local-time  = 03:01:43
| image = GuateQuake1976Patzicia.jpg
| image alt =
| map2 = {{Location map | Central America#Guatemala
| AlternativeMap = Relief map of Central America.jpg
| relief = yes
| label = 
| lat = 15.32
| long = -89.10
| mark = Bullseye1.png
| marksize = 40
| position = bottom
| width = 260
| float = right
| caption = }} 
| map_alt =
| magnitude = 7.5 {{M|w|link=y}}
| depth = {{convert|5|km|mi|0}}
| location = {{coord|15.32|-89.10|region:GT_type:event|display=inline,title}}
| fault = [[Motagua Fault]]
| type = [[Fault (geology)#Strike-slip faults|Strike-slip]]
| countries affected = [[Guatemala]]<br>[[British Honduras|Belize]]
| intensity = {{MMI|IX}}<ref name="NOAA" />
| tsunami =
| casualties = 23,000 fatalities, 76,000 injured
}}

The '''1976 Guatemala earthquake''' struck on February 4 at {{tooltip|03:01:43 local time|09:01:43 (UTC-6)}} with a [[Moment magnitude scale|moment magnitude]] of 7.5. The shock was centered on the [[Motagua Fault]], about 160&nbsp;km northeast of [[Guatemala City]] at a depth of {{convert|5|km|sp=us}} near the town of [[Los Amates]] in the department of [[Izabal Department|Izabal]].<ref name="NOAA" />

The earthquake ruptured a continuous length of 240&nbsp;km along the Motagua fault and might have extended further to the east and west but was blocked by vegetation and swamps.

Cities throughout the country suffered damage, and most [[adobe]] type houses in the outlying areas of Guatemala City were destroyed. The earthquake struck during the early morning (at 3:01 am, local time) when most people were asleep. This contributed to the high death toll of 23,000. Approximately 76,000 were injured, and many thousands left [[homeless]]. Some of the areas affected went without [[electricity]] and communications for days.

The main shock was followed by thousands of [[aftershock]]s, some of the larger ones causing additional damage and loss of life.<ref>[https://earthquake.usgs.gov/regional/world/events/1976_02_04.php Historic Earthquakes] {{webarchive|url=https://web.archive.org/web/20070410073512/http://earthquake.usgs.gov/regional/world/events/1976_02_04.php |date=2007-04-10 }}</ref>

== Seismic data ==

The quake's epicentre was located near the town of [[Los Amates]], in the eastern part of the [[Motagua Fault]], a left-lateral [[strike-slip fault]] that forms part of the tectonic boundary between the [[North American plate]] and the [[Caribbean plate]].<ref name="NOAA" /> Ground shaking was felt during approximately 39 seconds, and caused visible rupturing over {{convert|230|km|mi|0}} along the Motagua fault, while the inferred length of faulting—based on aftershock registration—was estimated at {{convert|300|km|mi|0}}. Average horizontal displacement along the Motagua fault was {{convert|100|cm|ft|0}} with a maximum displacement of {{convert|326|cm|ft|0}}.<ref name="NOAA">{{cite web|title =Significant Earthquake Information|url=https://www.ngdc.noaa.gov/hazel/view/hazards/earthquake/event-more-info/4711|publisher=National Geophysical Data Center / World Data Service (NGDC/WDS): NCEI/WDS Global Significant Earthquake Database. NOAA National Centers for Environmental Information.| doi=10.7289/V5TD9V7K|access-date=22 March 2024}}</ref>

Maximum seismic intensity ([[Modified Mercalli intensity scale|MMI]] IX) was located in the [[Mixco]] area, some sections of Guatemala City and in [[Gualán]]. A seismic intensity of MM VI covered an area of 33,000&nbsp;km<sup>2</sup>.<ref name="NOAA" /> [[Soil liquefaction]] and [[sand boil]]s were observed in several locations with high seismic intensity. The main quake activated secondary fault zones, including the [[Mixco fault]], located in a densely populated area just north-west of Guatemala City.

== Victims and damage ==
The most heavily affected area covered some 30,000&nbsp;km<sup>2</sup>, with a population of 2.5 million. In addition to the 23,000 reported fatalities and injuries to 77,000 people, approximately 258,000 houses were destroyed, leaving about 1.2 million people homeless. 40% of the national hospital infrastructure was destroyed, while other health facilities also suffered substantial damage.<ref>Olcese (e.a.), 1977</ref>

== International reaction ==

Immediately after the earthquake, President [[Kjell Eugenio Laugerud García]] invited most of the foreign ambassadors to tour the affected regions by helicopter, which prompted them to quickly ask for help in their home countries. For example, the United States of America rebuilt most of the roads, and Canada and Belgium each rebuilt a village.{{Citation needed|date=April 2011}}

Within days of the initial rupture the USGS sent a team of geologist to document the fault rupture and its effects. This team headed by George Plafker traveled the entire length of the fault by helicopter and was able to clearly trace its location. During this expedition several thousand photographs were collected including 1:10,000 aerial photographs collected by plane. In 2021 this analog data was digitized and georeferenced in order to build a database to assist in relocating the initial rupture location. During the summer of 2021 a team of geologist successfully relocated the fault rupture at 10 different locations. At the locations no evidence of post 1976 fault creep was observed.<ref>2021, McEnaney T., and Niemi, T.M., Building a georeferenced database for the 1976 
Guatemalan Earthquake rupture of the Motagua fault system along the North American-
Caribbean Plate Boundary: Geological Society of America Abstracts with Programs, v. 53, no. 6, 
https://doi.org/10.1130/abs/2021AM-370687</ref>

== Aftershocks ==
Several aftershocks, ranging from 5.2 to 5.8 {{M|w|link=y}} caused additional casualties and hampered relief efforts.

<div style="font-size:0.9em;">
{|
|-
|'''Date'''
|'''Origin Time'''
|'''Coordinates'''
|'''Location'''
|'''Depth'''
|'''Magnitude'''
|-
|Feb. 04 1976
|09.30.28.3
|{{coord|14.7|N|90.6|W||}}
|7&nbsp;km NNE of [[Mixco]]
|5&nbsp;km
|5.8 {{M|w}}
|-
|Feb. 06 1976
|04.11.03.3
|{{coord|14.6|N|91.1|W||}}
| 6&nbsp;km SSE of [[San Lucas Tolimán]]
|5&nbsp;km
|4.8 {{M|w}}
|-
|Feb. 06 1976
|18.11.59.2
|{{coord|14.3|N|90.2|W||}}
|11&nbsp;km ENE of [[Cuilapa]]
|5&nbsp;km
|5.2 {{M|w}}
|-
|Feb. 06 1976
|18.19.17.7
|{{coord|14.7|N|90.6|W||}}
|5&nbsp;km ENE of [[San Pedro Sacatepéquez, Guatemala|San Pedro Sacatepéquez]]
|5&nbsp;km
|5.8 {{M|w}}
|-
|Feb. 08 1976
|08.13.51.9
|{{coord|15.7|N|88.5|W||}}
| 13&nbsp;km SE of [[Puerto Barrios]]
|5&nbsp;km
|5.7 {{M|w}}
|-
|Feb. 09 1976
|11.44.46.7
|{{coord|15.3|N|89.1|W||}}
| 30&nbsp;km WSW of [[Morales, Guatemala|Morales]]
|5&nbsp;km
|5.1 {{M|w}}
|-
|Feb. 10 1976
|06.17.43.0
|{{coord|15.0|N|89.7|W||}}
| 18&nbsp;km WNW of [[Zacapa]]
|5&nbsp;km
|4.7 {{M|w}}
|-
|Mar. 07 1976
|02.54.05.4
|{{coord|14.9|N|90.9|W||}}
| 14.5&nbsp;km SW of [[Joyabaj]]
|5&nbsp;km
|4.8 {{M|w}}
|-
|Mar. 07 1976
|03.15.40.3
|{{coord|14.7|N|90.5|W||}}
|[[Chinautla]] (9&nbsp;km North of Guatemala City)
|5&nbsp;km
|4.9 {{M|w}}
|}</div>
<div style="font-size:0.9em;">Source: Wayerly Person, William Spence, and James W. Dewey. Main event and principal aftershocks from teleseismic data. In: Guatemalan Earthquake of February 4, 1976, A Preliminary Report.</div>

==In popular culture==
Scenes of the earthquake's aftermath, filmed on February 6, 1976, were featured in the Italian [[Mondo film]] ''[[Savana violenta]]'', directed by Antonio Climati and Mario Morra.

== Image gallery ==

<gallery class="center" widths="200px" heights="200" perrow="3" align=center Caption="Guatemala City">
Image:GuateQuake1976HotelTerminalA.jpg|''Hotel Terminal''
Image:GuateQuake1976CiudadFoundationFailures.jpg|''Landslide in [[Guatemala City]]''
Image:GuateQuake1976Ciudad50.jpg|''Guatemala City centre''
</gallery>

<gallery class="center" widths="200px" heights="200" perrow="3" align=center Caption="Antigua Guatemala">
File:Companiadejesus.jpg|Society of Jesus church ruins in 1896.
File:La Compania de Jesus.jpg|Jesuit church façade, stabilized in the 21st century.  Note the damage to the structure after the 1976 earthquake.
File:Señoradelcarmen.jpg|"Nuestra Señora del Carmen" Church in 1896.
File:Iglesia_del_Carmen_(3746568616).jpg|Same church in 2010, after the 1976 earthquake.
File:Recoleccion1875a.jpg|[[La Recolección Architectural Complex|Iglesia de La Recolección]] in 1875. The only surviving arch was a symbol of Antigua Guatemala ruins for many years.
File:LaRecoleccion.Antigua.jpg|La Recolección in 2005. The 1917 and 1976 earthquakes destroyed what was left of the iconic arch.
</gallery>

<gallery class="center" widths="200px" heights="200" perrow="3" align=center Caption="Rural Guatemala">
Image:GuateQuake1976BentRailsA.jpg|''Bent rails in Gualán''
Image:Guatemala1976Earthquake14ct.jpg|''Motagua Fault in Gualán''
Image:GuateQuake1976Patzicia.jpg|''[[Patzicía]] destroyed''
File:Puente de Agua Caliente - on road to Coban.jpg|''Puente de Agua Caliente, on the road to Cobán''
</gallery>

==See also==
*[[List of earthquakes in 1976]]
*[[List of earthquakes in Guatemala]]

==Notes==
{{reflist}}

== References ==
{{refbegin}}
* {{cite web|last=Bates|first=F.L.|author2=Killian, C.D.|author3=Daniel G.R.|author4=Klein, R.E.|name-list-style=amp|title=Emergency Food Programmes following the 1976 Guatemalan Earthquake: An Evaluation: Final Report|publisher=USAID|location=Washington|year=1979|url=http://pdf.usaid.gov/pdf_docs/PNAAQ014.pdf}}
* {{cite journal|last1=Bucknam|first1=R.C.|first2=George|last2=Plafker|first3=R.V.|last3=Sharp|title=Fault movement (afterslip) following the Guatemala earthquake of February 4, 1976|journal=Geology|volume=6|issue=3|pages=170–173|date=March 1978|doi=10.1130/0091-7613(1978)6<170:FMAFTG>2.0.CO;2|bibcode = 1978Geo.....6..170B }}
* {{cite journal|last=Langer |first=C.V.|author2=G.A. Bollinger|title=Secondary faulting near the terminus of a seismogenic strike-slip fault: aftershocks of the 1976 Guatemala earthquake|journal=Bulletin of the Seismological Society of America|date=1979 |volume=69|issue=2|pages=427–444|doi=10.1785/BSSA0690020427 |bibcode=1979BuSSA..69..427L |s2cid=131684154 }}
* {{cite journal|last=Matumoto|first=Tosimatu|author2=Latham, Gary V.|title=Aftershocks of the Guatemalan earthquake of February 4, 1976 |journal=Geophysical Research Letters|volume=3|issue=10|pages=599–602|doi=10.1029/GL003i010p00599|bibcode=1976GeoRL...3..599M|year=1976}}
* {{cite web|last=Olcese|first=Orlando|author2=Ramón Moreno|author3=Francisco Ibarra|name-list-style=amp|title=The Guatemala Earthquake Disaster of 1976: A Review of its Effects and of the contribution of the United Nations family|publisher=UNDP, Guatemala|date=July 1977 |url=http://cidbimena.desastres.hn/docum/crid/Septiembre-Octubre2005/CD-1/pdf/eng/doc4146/doc4146.htm}}
* {{cite journal|last=Olson|first=Robert A.|author2=Richard Stuart Olson|title=The Guatemala earthquake of 4 February 1976: Social science observations and research suggestions|journal=Mass Emergencies|pages=69–81|year=1977|url=http://www.massemergencies.org/v2n2/Olson_v2n2.pdf|access-date=2010-04-29|archive-url=https://web.archive.org/web/20110727070618/http://www.massemergencies.org/v2n2/Olson_v2n2.pdf|archive-date=2011-07-27|url-status=dead}}
* {{cite journal|last=Plafker|first=G.|authorlink=George Plafker|title=Tectonic aspects of the Guatemala earthquake of 4 February 1976 |journal=[[Science (journal)|Science]]|volume=193|issue=4259|pages=1201–1208|year=1976|doi=10.1126/science.193.4259.1201|pmid=17837005|bibcode=1976Sci...193.1201P|s2cid=335381 }}
* {{cite report|last=Plafker|first=G.|author2=M.G. Bonilla|author3=S.B. Bonis|name-list-style=amp |title=Geologic effects in the Guatemala Earthquake of February 4, 1976, a preliminary Report. Professional Paper 1002|pages=38–51|publisher=United States Geological Survey|location=Washington|year=1976}}
* {{cite journal|author=USGS|title=Guatemalan Quake Culprit Fault Identified |journal=Earthquake Information Bulletin|volume=8|issue=3|date=May–June 1976}}
* {{cite journal|last=Young|first=Christopher J.|author2=Thorne Lay|author3=Christopher S. Lynnes|name-list-style=amp|authorlink2=Thorne Lay|title=Rupture of the 4 February 1976 Guatemalan earthquake|journal=Bulletin of the Seismological Society of America|volume=79|issue=3|pages=670–689 |date=June 1989}}
{{refend}}

== External links ==
{{Commons category}}
*[https://web.archive.org/web/20110725085746/http://libraryphoto.cr.usgs.gov/cgi-bin/show_picture.cgi?ID=ID.%20GUATEMALA%20EARTHQUAKE%2052ct USGS Map]
*[https://web.archive.org/web/20150923103122/http://larryrichman.org/guatemala-earthquake-1976/ Guatemala Earthquake 1976 – photos and personal accounts]
*{{EQ-isc-link|717474}}

{{Earthquakes in 1976}}
{{Guatemala topics}}
{{Authority control}}

[[Category:1976 earthquakes|Guatemala Earthquake, 1976]]
[[Category:1976 in Guatemala|Earth]]
[[Category:Earthquakes in Guatemala|1976 Guatemala]]
[[Category:February 1976 events in North America]]
[[Category:Natural disasters in Belize]]
[[Category:Strike-slip earthquakes]]