1969 Portugal earthquake

Earthquake in Portugal and Morocco April 2024 1969 Portugal earthquake 1969-02-28 02:40:32 812637 iscgem812637 1969 02 28 yes 02:40:32 Morocco#Portugal topographic 7.8 w yhttp://www.ngdc.noaa.gov/nndc/struts/results?eq_0=4477&t=101650&s=13&d=22,26,13,12&nd=display https://web.archive.org/web/20180914022407/https://www.ngdc.noaa.gov/nndc/struts/results?eq_0=4477&t=101650&s=13&d=22,26,13,12&nd=display dead 14 September 2018 Comments for the Significant Earthquake NGDC August 27, 2010 22.0 km mi on 7 36.017 -10.950 inline,title Portugal, Morocco 1.14 m 1 on 3 runups 6.3 w y Feb 28 at 04:25:35 UTC 13 killed 80 injured The 1969 Portugal earthquake struck western Portugal and Morocco on 28 February at 02:40 UTC. Originating west of the Strait of Gibraltar, the earthquake registered a magnitude of 7.8 and the maximum felt intensity was VII (Very strong) on the Mercalli intensity scale. In total, 13 people died and 80 sustained minor injuries. It was the largest earthquake to hit Portugal since the 1755 Lisbon earthquake.https://www.dn.pt/arquivo/diario-de-noticias/sismo-1969-o-mar-borbulhou-e-o-pais-saiu-a-rua-em-pijama-10630935.html Sismo 1969. O mar borbulhou e o país saiu à rua em pijama Diario de Noticias Henriques Graça February 28, 2019 March 10, 2022 pt Tectonic setting Geology of the Iberian Peninsula The epicenter of the earthquake lies within a diffuse zone of seismicity known as the Azores–Gibraltar seismic belt,Fukao Y. 1973 Thrust faulting at a lithospheric plate boundary the Portugal earthquake of 1969 Earth and Planetary Science Letters 18 2 205–216 10.1016/0012-821X(73)90058-7 1973E&PSL..18..205F which marks the boundary between the African plate and the Eurasian plate. The deformation at this plate boundary is transpressional in style, with dextral (right lateral) strike-slip accompanied by slow convergence (4 mm/yr).Grandin R. Borges, J.F. Bezzeghoud, M. Caldeira, B. Carrilho, F. amp 2007 Simulations of strong ground motion in SW Iberia for the 1969 February 28 (Ms = 8.0) and the 1755 November 1 (M ~ 8.5) earthquakes – II. Strong ground motion simulations Geophysical Journal International 171 2 807–822 http://www.ipgp.fr/~grandin/Raphael_Grandin_personal_web_page/Publications_files/Grandin_et_al_2007a_GJI_1755_Velocity_Model.pdf February 13, 2011 2007GeoJI.171..807G 10.1111/j.1365-246X.2007.03571.x free Linear bathymetric features within this zone, such as the SW–NE trending Gorringe Bank, are thought to be a result of reverse faulting. Investigations using multibeam swathe bathymetry have revealed additional SW–NE trending reverse faults and fold axes and a set of WNW–ESE trending lineaments, interpreted as strike-slip faults. The earthquake was located within the Horseshoe Abyssal Plain, where active reverse faulting has been imaged on seismic reflection data.Zitellini N. Grácia E. Matias L. Terrinha P. Abreu M.A. DeAlteris G. Henriet J.P. Dañobeitia J.J. Masson D.G. Mulder T. Ramella R. Somoza L. Diez S. amp 2009 The quest for the Africa–Eurasia plate boundary west of the Strait of Gibraltar Earth and Planetary Science Letters 280 1–4 13–50 10.1016/j.epsl.2008.12.005 2009E&PSL.280...13Z http://www.vliz.be/imisdocs/publications/227936.pdf Damage and casualties At magnitude 7.8, the earthquake was considered very powerful. The resulting damage killed 13 people (11 in Morocco and 2 in Portugal). Damage to local buildings was "moderate", according to the United States Geological Survey. Overall, structures were prepared for the earthquake and responded well, sustaining slight, if any, damage.https://earthquake.usgs.gov/learn/today/index.php?month=2&day=28&submit=View+Date Earthquake History for February 28th United States Geological Survey December 18, 2009 February 28, 2010 Characteristics The earthquake is interpreted to have resulted from movement on a southeast-dipping reverse fault. Analysis of seismigrams of the earthquake revealed two subevents comprised the rupture process. The first subevent, a pure thrust-faulting mechanism, occurred during the first 15 seconds of the rupture. Twenty seconds after the rupture onset, a larger subevent occurred with a strike-slip mechanism at shallower depths, reaching the seafloor.Grimison Nina L. Chen Wang-Ping Source mechanisms of four recent earthquakes along the Azores–Gibraltar plate boundary Geophysical Journal International 1988 92 3 391–401 10.1111/j.1365-246X.1988.tb00003.x 11 July 2025 free See also List of earthquakes in 1969 List of earthquakes in Portugal List of earthquakes in Morocco 1761 Portugal earthquake References ISC-GEM Global Instrumental Earthquake Catalogue (1900–2009) http://www.isc.ac.uk/iscgem/index.php ISC 2014 International Seismological Centre Version 1.05 PAGER-CAT Earthquake Catalog https://earthquake.usgs.gov/static/lfs/data/pager/catalogs/ September 4, 2009 United States Geological Survey Version 2008_06.1 External links 812637 Category:Earthquakes in Portugal Portugal Earthquake, 1969 Category:Earthquakes in Morocco Earthquake Category:1969 in Morocco Category:1960s tsunamis