1959 Coatzacoalcos earthquake

Earthquake in Mexico 1959 Coatzacoalcos earthquake 1959-08-26 08:25:37 882734 iscgem882734 1959 08 26 02:25:37 CST Thrust August 26: 9:00 a.m., noon, 9:30 p.m.August 27: 3:45 a.m. Mexico 6.4 w y 21.0 km mi 0 18.22 N 94.42 W type:event_region:MX-VER inline,title Mexico 8 25 dead, 200 injured The 1959 Coatzacoalcos earthquake (also known as the Jáltipan earthquake) occurred at 02:25 local time on August 26 near the Mexican state of Veracruz. The earthquake measured 6.4 w at a depth of 21 km, and had a maximum Modified Mercalli intensity of VIII (Severe). It had an epicenter immediately off the coast of Coatzacoalcos (in the Gulf of Mexico). The shallow back-arc thrust faulting earthquake damaged the cities of Acayucan, Coatzacoalcos, Jáltipan and Minatitlán. A total of 25 people died, including 10 from Jáltipan while a further 200 were injured. The Middle America Trench, a subduction zone that borders the southwestern coast of Mexico and Central America, accounts for much of the seismicity in Mexico. The eastern side of the country near the Gulf of Mexico rarely experiences large earthquakes although they have been recorded around the Veracruz area, where seismicity is higher compared to other parts of the gulf. Seismicity in the gulf is attributed to back-arc compression due to subduction. Tectonic setting Geography of Mexico left|thumb|230px|The subduction zone off Mexico's Pacific coast. Mexico is one of the most seismically active regions in the world; located at the boundary of at least three tectonic plates. The west coast of Mexico lies at a convergent plate boundary between the Cocos plate and North American plate. The Cocos plate, consisting of denser oceanic lithosphere, subducts to the northeast beneath the less dense continental crust of the North American plate. Most of the Mexican landmass is situated on the North American plate and is moving westward. Because oceanic crust is relatively dense it subducts beneath the buoyant continental crust of the Mexican landmass. Subduction off the Pacific coast of Mexico occurs along the Middle America Trench along the southern coast of Mexico. The subduction zone is seismically active and responsible for large earthquakes—a magnitude 8.1 earthquake in 1985 caused over 9,500 fatalities. Earthquake Thrust tectonics The earthquake had a focal mechanism corresponding to thrust faulting at a depth of 21 km. The source fault is characterized by a high-angle plane oriented parallel to the Veracruz coast. A similar earthquake in the same area in 1967 demonstrated thrust faulting mechanism at 26 km depth. In 1946, a magnitude 6.0 also struck the same place with a similar focal mechanism. These earthquakes are not associated with rupture on the subduction zone off Mexico's west coast. The focal depth of these events are unusually deep for most intracontinental earthquakes, where the depth is usually shallower than 15 km. This suggests the earthquakes occurred inside the mantle, beneath the 20 km-thick transitional crust. The Gulf of Mexico, where the Jáltipan earthquake occurred, is a region of low seismicity. This area represents a passive margin and is considered aseismic. At the Isthmus of Tehuantepec, intermediate-depth earthquakes associated with the subducting Cocos plate are common. However, there is a region of shallow seismicity around Veracruz and Tabasco in the southwestern part of the gulf where earthquakes are of low magnitude. Shallow seismic activity on the isthmus is associated with back-arc compression within the shallow crust. Deformation of the crust is accommodated by crustal shortening on thrust faults. This compressive force is brought on by west coast subduction, as well as subduction of the Tehuantepec Ridge. Damage The combined effects of structural or foundation failure and soil liquefaction earned the earthquake a maximum Modified Mercalli intensity of VIII (Severe) in Jáltipan, Coatzacoalcos and Minatitlán. Building failures occurred at Coatzacoalcos and Minatitlán. Ground subsidence due to liquefaction was observed at the port of Coatzacoalcos. Altogether, 450 homes and other dwellings, a school, two churches and a railroad station were total losses. Twenty-five people died and 200 were injured. Jáltipan was nearly destroyed—10 people were killed and 138 were injured—including 45 in serious condition. A navy workshop in Coatzacoalcos subsided by a meter, cracking its floor. Petrol storage facilities at the port were damaged. A highway and the city streets suffered cracks. The tower of the San Francisco de Asís church was severely compromised and needed to be demolished. In Minatitlán, an oil pipeline ruptured and spilled. In Acayucan, 20 percent of the city's buildings were demolished and there were 20 wounded. The highway between Coatzacoalcos and Minatitlán were filled with cracks up to 2 m wide and deep. From Santa Marta, residents reported a large flame towering 60 m over the Sierra de los Tuxtlas range. Aftermath Volunteers rushed to the fire brigade in response to those injured and to remove bodies from the rubble. Ambulances from Red Cross organizations arrived shortly. The Governor of Veracruz, Antonio Modesto Quirasco, along with members of his cabinet, arrived at Jáltipan on the night of August 26. An establishment (Patronato Pro Recuperación Social de Jáltipan) was formed to help raise funds for the reconstruction of Jáltipan. The representative of President Adolfo López Mateos, Fernando López Arias, arrived the following day to overlook and manage reconstruction projects. Many socialites contributed to food distribution. See also List of earthquakes in 1959 List of earthquakes in Mexico References OB 882734 Significant Earthquake Database https://www.ngdc.noaa.gov/hazel/view/hazards/earthquake/event-more-info/4201 National Geophysical Data Center / World Data Service (NGDC/WDS) National Geophysical Data Center, NOAA 10.7289/V5TD9V7K 1959 Data Set G. Suárez Reverse faulting in the Isthmus of Tehuantepec: Backarc deformation induced by the subduction of the Tehuantepec ridge Cenozoic Tectonics and Volcanism of Mexico 2000 334 263–268 10.1130/0-8137-2334-5.263 https://www.researchgate.net/publication/287470137 Geological Society of America 9780813723341 Hugo Delgado-Granados Gerardo J. Aguirre-Díaz Joann M. Stock GSA Special Papers S. K. Singh J. F. Pacheco X. Pérez-Campos M. Ordaz E. Reinoso The 6 September 1997 (Mw4.5) Coatzacoalcos-Minatitlán, Veracruz, Mexico earthquake: implications for tectonics and seismic hazard of the region Geofísica Internacional 2015 54 3 289–298 10.1016/j.gi.2015.08.001 2015GeofI..54..289S free F. C. Martínez Cuando un terremoto devastó el municipio de Jáltipan http://alornoticias.com.mx/noticias/cuando-un-terremoto-devasto-el-municipio-de-jaltipan/ 4 March 2022 Alor Noticias 31 August 2017 es R. J. Marsal Behavior of a Sandy Uniform Soil During the Jaltipan Earthquake, Mexico Proc. Fifth Int. Conf. Soil Mech. And Foundation Eng 1961 1 229–234 https://www.issmge.org/uploads/publications/1/40/1961_01_0039.pdf International Society for Soil Mechanics and Geotechnical Engineering H. M. Benz R. L. Dart A. Villaseñor G. P. Hayes A. C. Tarr K. P. Furlong S. Rhea Seismicity of the Earth 1900–2010 Mexico and Vicinity https://pubs.usgs.gov/of/2010/1083/f/ United States Geological Survey Open-File Report 2010-1083-F R. D. de Cossias Foundation failures during the Coatzacoalcos (Mexico) earthquake of 26 August 1959 https://www.iitk.ac.in/nicee/wcee/article/vol.1_session5_473.pdf conference Proc. 2nd World Conf. on Earthquake Engineering 1960 Further reading Luna Bauza, C. (1992): Sismos en el estado de Veracruz (Gobierno del Estado de Veracruz-Llave, Mexico) es. Merino y Coronado J. 1960 El terremoto de Jaltipan, Ver. del 26 de Agosto de 1959 The earthquake of Jaltipan, Veracruz on August 26, 1959 Anales del Instituto de Geofísica 6 89–137 0076-7182 External links 882734 Coatzacoalcos earthquake Coatzacoalcos earthquake Coatzacoalcos earthquake Coatzacoalcos earthquake Category:Earthquakes in Mexico Category:Gulf of Mexico Category:History of the Gulf of Mexico Coatzacoalcos earthquake, 1959