1976 Guatemala earthquake

1976 Guatemala earthquake

File:GuateQuake1976Patzicia.jpg
Date	February 4, 1976 (1976-02-04)
Origin time	09:01:43 UTC-6
Magnitude	7.5 Mw
Depth	5 kilometres (3 mi)
Epicenter
Type	Strike-slip
Areas affected	Guatemala
Max. intensity	IX (Violent)
Casualties	23,000 fatalities, 76,000 injured

The 1976 Guatemala earthquake struck on February 4 at 03:01:43 local time with a moment magnitude of 7.5. The shock was centered on the Motagua Fault, about 160 km northeast of Guatemala City at a depth of 5 kilometers (3.1 mi) near the town of Los Amates in the department of Izabal.

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 areas went without electricity and communications for days.

The main shock was followed by thousands of aftershocks, some of the larger ones causing additional damage and loss of life.

Seismic data

See also: List of earthquakes in Guatemala

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 the tectonic boundary between the North American plate and the Caribbean plate. Ground shaking was felt during approximately 39 seconds, and caused visible rupturing over 230 km along the Motagua fault, while the inferred length of faulting—based on aftershock registration—was estimated at 300 km. Average horizontal displacement along the Motagua fault was 100 cm, with a maximum displacement of 326 cm.

Maximum seismic intensity (MM 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 km². Liquefaction and sand boils 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 km², with a population of 2.5 million. Some 23,000 people were reported dead and 77,000 wounded. 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.

International reaction

Very soon after the earthquake, the then 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 the Canadians and Belgians each rebuilt a village.

Aftershocks

Several heavy aftershocks, ranging from 5.2 to 5.8 M_w caused additional casualties and hampered relief efforts.

Date	Origin Time	Coordinates	Location	Depth	Magnitude
Feb. 04 1976	09.30.28.3		7 km NNE of Mixco	5 km	5.8 Mw
Feb. 06 1976	04.11.03.3		6 km SSE of San Lucas Tolimán	5 km	4.8 Mw
Feb. 06 1976	18.11.59.2		11 km ENE of Cuilapa	5 km	5.2 Mw
Feb. 06 1976	18.19.17.7		5 km ENE of San Pedro Sacatepéquez	5 km	5.8 Mw
Feb. 08 1976	08.13.51.9		13 km SE of Puerto Barrios	5 km	5.7 Mw
Feb. 09 1976	11.44.46.7		30 km WSW of Morales	5 km	5.1 Mw
Feb. 10 1976	06.17.43.0		18 km WNW of Zacapa	5 km	4.7 Mw
Mar. 07 1976	02.54.05.4		14.5 km SW of Joyabaj	5 km	4.8 Mw
Mar. 07 1976	03.15.40.3		Chinautla (9 km North of Guatemala City)	5 km	4.9 Mw

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.

Image gallery

• Guatemala City
• 

  Hotel Terminal

• GuateQuake1976CiudadFoundationFailures.jpg

  Landslide in Guatemala City

• GuateQuake1976Ciudad50.jpg

  Guatemala City centre

• Antigua Guatemala
• Companiadejesus.jpg

  Society of Jesus church ruins in 1896.

• La Compania de Jesus.jpg

  Jesuit church façade, stabilized in the 21st century. Note the damage to the structure after the 1976 earthquake.

• Señoradelcarmen.jpg

  "Nuestra Señora del Carmen" church en 1896.

• 

  Same church in 2010, after the 1976 earthquake.

• 

  Iglesia de La Recolección in 1875. The only surviving arch was a symbol of Antigua Guatemala ruins for many years.

• 

  La Recolección in 2005. The 1917 and 1976 earthquakes destroyed what was left of the iconic arch.

• Rural Guatemala
• GuateQuake1976BentRailsA.jpg

  Bent rails in Gualán

• Guatemala1976Earthquake14ct.jpg

  Motagua Fault in Gualán

• GuateQuake1976Patzicia.jpg

  Patzicía destroyed

External links

• USGS Map
• Guatemala Earthquake 1976 - photos and personal accounts