The 1959 Coatzacoalcos earthquake occurred on the morning of August 26 near the Mexican state of Veracruz. Measuring 6.4 Mw with an epicenter immediately off the coast of Coatzacoalcos (in the Gulf of Mexico), it caused severe damage and at least 25 deaths.
   | |
| UTC time | 1959-08-26 08:25:37 |
|---|---|
| ISC event | 882734 |
| USGS-ANSS | ComCat |
| Local date | August 26, 1959 |
| Local time | 2:25:37 CST |
| Duration | 35 seconds |
| Magnitude | 6.4 Mw [1] |
| Depth | 26.0 km (16 mi) [2] |
| Epicenter | 18°13′N 94°25′W / 18.22°N 94.42°W |
| Type | Thrust |
| Areas affected | Mexico |
| Total damage | Severe [3] |
| Max. intensity | VIII (Severe) [4] |
| Tsunami | No |
| Aftershocks | August 26: 9:00 am, 12:00 pm, 9:30 pm August 27: 3:45 am[5] |
| Casualties | 25 dead, 200 injured [3] |
Tectonic settingEdit
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 beneath the less dense continental crust of the North American Plate. Most of the Mexican landmass is situated on the North American plate moving westward. Because the oceanic crust is relatively dense, when the bottom of the Pacific Ocean meets the lighter continental crust of the Mexican landmass, the ocean floor subducts beneath the North American plate creating the Middle America Trench along the southern coast of Mexico. Occasionally, the contact interface or subduction zone megathrust release elastic strain during earthquakes. Large and sudden uplift of the seafloor can produce large tsunamis when such earthquakes occur.[6]
EarthquakeEdit
The earthquake had a focal mechanism corresponding to shallow thrust faulting at a depth of 21 km. A similar earthquake in the same area in 1967 also demonstrated thrust mechanism of faulting. 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 Guf of Mexico, where the quake occurred, is a region of low seismic activity. However, at the Isthmus of Tehuantepec, there is a region of shallow seismic acticity. 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. The compressive force is brought on by west coast subduction, as well as the subduction of the Tehuantepec Ridge.[4]
DamageEdit
Lasting 35 seconds, the earthquake caused severe building damage in Veracruz. An estimated 25 people died and 200 others suffered injuries.[3] A maximum Mercalli intensity of VIII (Severe) was felt in Coatzacoalcos and Minatitlán, causing serious structural failure in buildings. At Jáltipan, the city was nearly destroyed; ten people were killed and 138 were injured. Ground subsidence due to liquefaction was observed at the port of Coatzacoalcos.[2] A navy workshop subsided by a meter, cracking the floor.[7] Petrol storage facilities at the port were damaged. A highway and 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% of the city's buildings were demolished and there were 20 wounded. From Santa Marta, residents reported a large flame towering 60 meters over the Sierra de los Tuxtlas range.[5]
AftermathEdit
Volunteers rushed to the fire brigade to respond to those injured and remove bodies from the rubble. Ambulances from red cross organizations arrived shortly. The Governor of Veracruz, Antonio Modesto Quirasco, along with members of hiscabinet, arrived at Jáltipan on the night of August 26. 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.[5]
See alsoEdit
ReferencesEdit
- ^ ISC-OB Event 882734 [IRIS].
- ^ a b Shri Krishna Singh; José Francisco Pacheco; Xyoli Pérez-Campos; Mario Ordaz; Eduardo Reinoso (2015). "The 6 September 1997 (Mw4.5) Coatzacoalcos-Minatitlán, Veracruz, Mexico earthquake: implications for tectonics and seismic hazard of the region". Geofísica Internacional. 54 (3): 289-298. doi:10.1016/j.gi.2015.08.001.
- ^ a b c National Geophysical Data Center / World Data Service (NGDC/WDS) (1959), Significant Earthquake Database (Data Set), National Geophysical Data Center, NOAA, doi:10.7289/V5TD9V7K
- ^ a b Suárez, Gerardo. "Reverse faulting in the Isthmus of Tehuantepec: Backarc deformation induced by the subduction of the Tehuantepec ridge". Cenozoic tectonics and volcanism of Mexico. Geological Society of America. 334: 263-268. doi:10.1130/0-8137-2334-5.263. ISBN 9780813723341.
- ^ a b c Florentino Cruz Martínez (31 August 2017). "Cuando un terremoto devastó el municipio de Jáltipan". Alor Noticias (in Spanish). Retrieved 4 March 2022.
- ^ Harley M. Benz; Richard L. Dart; Antonio Villaseñor; Gavin P. Hayes; Arthur C. Tarr; Kevin P. Furlong; Susan Rhea. "Seismicity of the Earth 1900–2010 Mexico and Vicinity" (Open-File Report 2010-1083-F). U.S. Geological Survey.
- ^ R. J. Marsal (1961). "Behavior of a Sandy Uniform Soil During the Jaltipan Earthquake, MexicoBehavior of a Sandy Uniform Soil During the Jaltipan Earthquake, Mexico" (PDF). Proc. Fifth Int. Conf. Soil Mech. and Foundation Eng. International Society for Soil Mechanics and Geotechnical Engineering. 1: 229-234.
External linksEdit
- The International Seismological Centre has a bibliography and/or authoritative data for this event.
- Roger Dias de Cossias (1960), "Foundation failures during the Coatzacoalcos (Mexico) earthquake of 26 August 1959" (PDF), Proc. 2nd World Conf. on Earthquake Engineering (conference)