The 1980 El Asnam earthquake occurred on October 10 at with a
moment magnitude
The moment magnitude scale (MMS; denoted explicitly with or Mw, and generally implied with use of a single M for magnitude) is a measure of an earthquake's magnitude ("size" or strength) based on its seismic moment. It was defined in a 1979 pape ...
of 7.1 and a maximum
Mercalli intensity
The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the eff ...
of X (''Extreme''). The shock occurred in the
Algeria
)
, image_map = Algeria (centered orthographic projection).svg
, map_caption =
, image_map2 =
, capital = Algiers
, coordinates =
, largest_city = capital
, relig ...
n town of El Asnam (now known as
Chlef
Chlef ( ar, الشلف, Berber: Clef) is the capital of Chlef Province, Algeria. Located in the north of Algeria, west of the capital, Algiers, it was founded in 1843, as Orléansville, on the ruins of Roman ''Castellum Tingitanum''. In 1962, i ...
). The shocks were felt over away, with the initial earthquake lasting 35 seconds.
It was the largest earthquake in Algeria, and was followed three hours later by a magnitude 6.2
aftershock
In seismology, an aftershock is a smaller earthquake that follows a larger earthquake, in the same area of the main shock, caused as the displaced crust adjusts to the effects of the main shock. Large earthquakes can have hundreds to thousand ...
. The earthquake created about of
surface rupture
In seismology, surface rupture (or ground rupture, or ground displacement) is the visible offset of the ground surface when an earthquake rupture along a fault affects the Earth's surface. Surface rupture is opposed by buried rupture, where the ...
and had a vertical slip of up to . No foreshocks were recorded.
The earthquake was found to have occurred very close to the epicenter of the
1954 Chlef earthquake
The 1954 Chlef earthquake struck Chlef Province in Algeria on September 9 at . The shock measured 6.7 on the moment magnitude scale and had a maximum Mercalli intensity of XI (''Extreme''). It destroyed Chlef, then named Orléansville, leaving ov ...
using joint epicenter determination techniques.
It occurred at a previously unknown reverse fault.
The earthquake was the largest in the
Atlas range since
1790.
In addition to the earthquake, weak tsunami waves were recorded on tide gauges.
The earthquake occurred at a populated region of Algeria, affecting 900,000 people. It destroyed 25,000 houses and made 300,000 inhabitants homeless.
In addition to destroying homes, the earthquake also demolished critical infrastructure, including the main hospital, the central mosque, and a girls' school. The hospital was damaged significantly enough that victims had to be transported more than away to the next nearest hospital. Both events caused considerable damage with at least 2,633 killed and 8,369 injured.
The earthquake caused approximately $5.2 billion in damage, which was 22% of Algeria's GDP at the time.
See also
*
1954 Chlef earthquake
The 1954 Chlef earthquake struck Chlef Province in Algeria on September 9 at . The shock measured 6.7 on the moment magnitude scale and had a maximum Mercalli intensity of XI (''Extreme''). It destroyed Chlef, then named Orléansville, leaving ov ...
*
List of earthquakes in 1980
This is a list of earthquakes in 1980. Only earthquakes of magnitude 6 or above are included, unless they result in damage and/or casualties, or are notable for some other reason. Events in remote areas will not be listed but included in statist ...
*
List of earthquakes in Algeria
Earthquakes in Algeria occur in the north part of the country, usually north of 35° N. latitude, and occasionally as submarine earthquakes in the Mediterranean Sea. On at least one occasion, this type of event has generated a destructive tsunami. ...
Notes
External links
*
{{Earthquakes in Algeria
El Asnam Earthquake, 1980
El Asnam Earthquake, 1980
1980
Events January
* January 4 – U.S. President Jimmy Carter proclaims a grain embargo against the USSR with the support of the European Commission.
* January 6 – Global Positioning System time epoch begins at 00:00 UTC.
* January 9 – ...
October 1980 events in Africa
1980 disasters in Algeria