The 1861 Mendoza earthquake occurred in the

province A province is almost always an administrative division within a country or state. The term derives from the ancient Roman '' provincia'', which was the major territorial and administrative unit of the Roman Empire's territorial possessions ou ...

of Mendoza,

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

on 20 March at 11:30 PM. It had an estimated magnitude of 7.2 on the scale and an intensity of IX–X on the

Mercalli scale 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 ...

. Its

hypocenter In seismology, a hypocenter or hypocentre () is the point of origin of an earthquake or a subsurface nuclear explosion. A synonym is the focus of an earthquake. Earthquakes An earthquake's hypocenter is the position where the strain energy ...

was located at an estimated depth of .

Tectonic setting

The city of Mendoza lies just to the east of the Precordillera structural belt, at the eastern margin of the

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

mountain belt. The ongoing

flat slab subduction Flat slab subduction is characterized by a low subduction angle (<30 degrees to horizontal) beyond the

seismogenic layer

of the Nazca Plate below the South American Plate is causing shortening in the over-riding plate that is concentrated in the Precordillera belt, with a rate of 4.5±1.7 mm per year, from

GPS The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sy ...

data. This shortening is expressed as

active Active may refer to: Music * ''Active'' (album), a 1992 album by Casiopea * Active Records, a record label Ships * ''Active'' (ship), several commercial ships by that name * HMS ''Active'', the name of various ships of the British Royal ...

thrust fault A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Thrust geometry and nomenclature Reverse faults A thrust fault is a type of reverse fault that has a dip of 45 degrees or less. If ...

ing. The two active thrust faults near Mendoza are the Peñas Thrust and the Cal Thrust, with the latter reaching the surface inside the city. This zone is one of the most seismically active parts of the Andes.

Earthquake

The earthquake is thought to have been caused by rupture of the Cal Thrust. The estimated magnitude of 7.2 is consistent with the estimated slip rate and frequency of ruptures along this fault, which suggest vertical offsets in the range 0.8–1.0 m for the last three to four earthquakes.

Damage

The earthquake devastated the provincial capital, Mendoza, killing somewhere in the range of 6,000 to 12,000 people, although even higher numbers have been suggested, with thousands more being injured. with thousands more being injured. Most of the buildings were destroyed, including the ''cabildo'' (colonial government house). Fires caused by rupturing of the gas supply for lighting in some stores lasted for four days. The obstruction of canals led to local flooding. The effects of liquefaction were widely reported and many large landslides were observed. The town was rebuilt in a nearby location, and the authorities moved to their new seat in 1863. The new constructions, which incorporated modern architectural styles, were markedly different from the old

colonial Colonial or The Colonial may refer to: * Colonial, of, relating to, or characteristic of a colony or colony (biology) Architecture * American colonial architecture * French Colonial * Spanish Colonial architecture Automobiles * Colonial (1920 au ...

buildings.

Notable deaths

Auguste Bravard (Pierre Joseph) Auguste Bravard (18 June 1803 – 28 March 1861) was a French mining engineer turned palaeontologist. He hunted fossils in the Vaucluse, Allier and his native Puy de Dôme. Biography Bravard emigrated to Argentina in the winter of ...

References

* Epicentro de los terremotos destructivos en Argentina (1692–2012
''Listado de Terremotos Históricos''

Tectonic setting

Earthquake

Damage

Notable deaths

See also

References

Further reading