El Asnam Algeria 1980 (CAR)

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Event ID
198010101225
Event name
El Asnam
Country
Algeria
Epicentral coordinates (long/lat)
POINT(1.4 36.14)
WKT GIS format
GEMECD contributing partner
CAR
Event narrative

On Friday 10th October 1980, at 13:25 local time, an earthquake of moment magnitude 7.1 and focal depth of 15 km struck the city of El Asnam in northern Algeria.

The main shock’s epicentre (36.14°N, 1.40°E) was just 10 km to the east of El Asnam (a city of 125,000 people, spread over an area of around 25 km2).

The earthquake was accompanied by low-angle thrust faulting with a rupture of around 32 km and maximum vertical displacement of 4.2 m as well as secondary fault ruptures.

In the USGS EXPO-CAT database it is estimated that during this earthquake 577,000 people were exposed to intensity VII or higher, of which around 46% were in rural areas.

The shaking lasted 35 seconds at the end of which much of the city and surrounding areas up to a distance of 60 km were in ruins. The towns of Beni-Rached, Zeboudja, El Abadia, El Attar, Oued-Fodda, Sendjas, El Karimia, Zabaddja, and the city of El Asnam sustained extensive damage. A maximum Modified Mercalli intensity of X was assigned to El Asnam, while intensities were generally higher on the upthrown fault block.

Numerous landslides blocked access to remote mountain villages for 3 to 5 days but no associated life loss has been reported.

Date of occurrence (UTC)
1980-10-10
date
Time of occurrence (UTC)
12:25:00
time
Date of occurrence (local)
1980-10-10
date
Time of occurrence (local)
13:25:00
time
Day of the week (local)
Friday
was it a holiday
Yes
boolean
Magnitude
7.1
Magnitude units
Moment (Mw)
Focal depth
15
km
Seismological data: source
USGS
Seismological data: comment

ShakeMap Atlas

Overall impact

El Asnam had been destroyed by an earthquake of magnitude 6.7 in September 1954 during French colonial rule and reconstructed by the French authorities (at the time it had the name of Orleansville).

Many of the buildings built immediately after the 1954 earthquake collapsed. In the city 23.5% of the existing buildings collapsed and 42.5% were seriously damaged. Fortunately the earthquake occurred during a day of rest. Schools, public buildings and major stores although totally destroyed were empty.

On the other hand the time of occurrence coincided with the time of prayer and many died in the collapsed Grand Mosque of El Asnam.

The death toll from this event, although never officially announced, is estimated to have reached 6500 people while an additional 9000 were injured (of which around 900 were admitted to hospitals).

In the city centre, the commercial-housing complex of Cité An Nasr with dimensions of 150*150 m collapsed entirely and it is not known how many of its more than 3000 occupants were rescued.

In the villages relatively fewer people were killed in spite of total collapse of numerous dwellings because many were outdoors.

In total around 7000 buildings and 50,000 dwelling units were classified as collapsed or destroyed. The number of long-term homeless was around 200,000 people.

The cost of the earthquake according to the Algerian government’s final estimate was 5 billion US$ (22% of Algeria’s GDP in 1980).

Overview data
Loss: Human Casualty
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People injured
9000
number
People injured: source
http://earthquake.usgs.gov/earthquakes/world/world_deaths.php
People injured: comment

Approximate number, the actual number was probably higher

People injured: status
Greater than

People seriously injured
1000
number
People seriously injured: source
CAR estimate
People seriously injured: comment

900 people were taken to hospital on the first 24 hrs

People seriously injured: status
Greater than

People missing
0
number

People killed
6000
number
People killed: source
Time Magazine, 27 Oct 1980
People killed: comment

Exact number has never been reported. Algerian government sources said on 17 October that more than 6000 bodies had been buried (Time Magazine, 27 Oct 1980).

People killed: status
Greater than

People killed due to ground shaking
6000
number
People killed due to ground shaking: source
Time Magazine, 27 Oct 1980
People killed due to ground shaking: status
Approximate

People dying post catastrophe due to shaking
0
number

People missing due to tsunami
0
number
People killed due to tsunami
0
number
People missing due to fire following
0
number
People killed due to fire following
0
number
People killed due to slope failures: comment

Landslides did occur and blocked access to mountain villages though casualties have not been reported.

Loss: Building damage
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Total number of buildings destroyed by shaking
1133
number
Total number of buildings destroyed by shaking: source
Haddar, F. (1990). Seismic Vulnerability of Urban Housing in Algeria and Related Risk Mitigation Strategies. Phd Thesis, Oxford Polytechnic, School of Architecture, Oxford 1990.
Total number of buildings destroyed by shaking: comment

Based on damage surveys in El Asnam city and another 23 villages. 945 in El Asnam and 188 outside El Asnam city.


Number of buildings damaged by shaking
6399
number
Number of buildings damaged by shaking: source
Haddar, F. (1990). Seismic Vulnerability of Urban Housing in Algeria and Related Risk Mitigation Strategies. Phd Thesis, Oxford Polytechnic, School of Architecture, Oxford 1990.
Number of buildings damaged by shaking: comment

Based on damage surveys in El Asnam city and another 23 villages. 5,044 in El Asnam and 1,355 outside El Asnam city.

Number of buildings damaged by shaking: status
Greater than

Number of dwellings destroyed by shaking
35450
number
Number of dwellings destroyed by shaking: source
UNESCO (1983): Assessment and mitigation of earthquake risk in the Arab region (251 pp), in p. 13

Number of dwellings damaged by shaking
30000
number
Number of dwellings damaged by shaking: source
http://iisee.kenken.go.jp/net/hara/algeria/alg19801010_3.htm
Number of dwellings damaged by shaking: comment

excl. the destroyed dwellings.

Number of dwellings damaged by shaking: status
Approximate

Loss: Socioeconomic
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People homeless
300000
number
People homeless: source
UNESCO (1983): Assessment and mitigation of earthquake risk in the Arab region (251 pp), in p.7
People homeless: status
Greater than

Direct economic loss
4000
million US$
Direct economic loss: source
UNESCO (1983): Assessment and mitigation of earthquake risk in the Arab region (251 pp), in p.7
Direct economic loss: comment

The damage to houses and public works has amounted to more than US$ 4 billion.
Munich Re reports 3,000 million US$ overall direct economic loss.

Direct economic loss: status
Greater than

Indirect economic loss: status
N/A

Insured loss
0
million US$
Insured loss: source
Munich Re

Demographics
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Total number of buildings: status
N/A