1980 El Asnam earthquake

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El Asnam earthquake
1980 El Asnam earthquake is located in Algeria
Algiers
Algiers
1980 El Asnam earthquake
Oran
Oran
Date October 10, 1980 (1980-10-10)
Origin time 12:25:25 UTC [1]
Magnitude 7.1 Mw [1]
Depth 10 km (6.2 mi) [1]
Epicenter 36°12′N 1°22′E / 36.2°N 1.37°E / 36.2; 1.37Coordinates: 36°12′N 1°22′E / 36.2°N 1.37°E / 36.2; 1.37 [1]
Type Dip-slip [2]
Areas affected Chlef Province
Algeria
Max. intensity X (Extreme) [3]
Tsunami .7 m (2 ft 4 in) [2]
Aftershocks 6.2 Mw Oct 10 at 15:39 UTC [2]
Casualties 2,633–5,000 dead [2]
8,369–9,000 injured [2]

The 1980 El Asnam earthquake occurred on October 10 at 13:25:25 local time with a moment magnitude of 7.1 and a maximum Mercalli intensity of X (Extreme). The shock occurred in the Algerian town of El Asnam (now known as Chlef). The shocks were felt over 550 km (340 mi) away, with the initial earthquake lasting 35 seconds.[4] It was the largest earthquake in Algeria, and was followed three hours later by a magnitude 6.2 aftershock. The earthquake created about 42 km (26 mi) of surface rupture and had a vertical slip of up to 4.2 m (14 ft). No foreshocks were recorded.[4] The earthquake was found to have occurred very close to the epicenter of the 1954 earthquake using joint epicenter determination techniques.[5][6] It occurred at a previously unknown reverse fault.[7]

The earthquake was the largest in the Atlas range since 1790.[5]

In addition to the earthquake, weak tsunami waves were recorded on tide gauges.[8]

The earthquake occurred at a populated region of Algeria, affecting 900,000 people. It destroyed 25,000 houses and made 300,000 inhabitants homeless.[5] 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 160 km (100 mi) away to the next nearest hospital. Both events caused considerable damage with at least 2,633 killed and 8,369 injured.[5][9] The earthquake caused approximately $5.2 billion in damage, which was 22% of Algeria's GDP at the time.[4]

See also[edit]

Notes[edit]

  1. ^ a b c d ISC (2015), ISC-GEM Global Instrumental Earthquake Catalogue (1900–2009), Version 2.0, International Seismological Centre 
  2. ^ a b c d e USGS (September 4, 2009), PAGER-CAT Earthquake Catalog, Version 2008_06.1, United States Geological Survey 
  3. ^ National Geophysical Data Center / World Data Service (NGDC/WDS), Significant Earthquake Database, National Geophysical Data Center, NOAA, doi:10.7289/V5TD9V7K 
  4. ^ a b c "El Asnam Algeria 1980 (CAR)". GEM ECD. Retrieved October 21, 2016. 
  5. ^ a b c d Ambraseys, Nicolas (1981). "The El Asnam (Algeria) earthquake of 10 October 1980; conclusions drawn from a field study". Quarterly Journal of Engineering Geology and Hydrogeology. Geological Society of London. 14: 143–148. doi:10.1144/gsl.qjeg.1981.014.02.05. 
  6. ^ Dewey, J. W. (1991), "The 1954 and 1980 Algerian earthquakes: Implications for the characteristic-displacement model of fault behavior", Bulletin of the Seismological Society of America, Seismological Society of America, 81 (2): 446–467 
  7. ^ "Comments for the Significant Earthquake". NOAA. Retrieved October 21, 2016. 
  8. ^ "Comments for the Significant Earthquake". NOAA. Retrieved October 21, 2016. 
  9. ^ "Thousands feared dead in Algerian quake". BBC. Retrieved October 20, 2016.