1787 New Spain earthquake
  | |
| Local date | 28 March 1787 |
|---|---|
| Local time | 11:30 |
| Magnitude | 8.6 Mw |
| Epicenter | 16°30′N 98°30′W / 16.5°N 98.5°W[1] |
| Type | Megathrust |
| Areas affected | New Spain |
| Total damage | Severe[1] |
| Tsunami | Yes |
| Casualties | 11 killed in the tsunami, total unknown |
The 1787 New Spain earthquake, also known as the San Sixto earthquake, occurred on 28 March at 11:30 local time (17:30
Tectonic setting
Southwestern Mexico lies above the convergent boundary where the Cocos Plate is being subducted below the North American Plate at a rate of 6.4 cm/yr. The dip of the subducting slab is about 15° as defined by focal mechanisms and earthquake hypocenters. Seismicity in this area is characterised by regular megathrust earthquakes along the plate interface.[2]
Earthquake
The earthquake was reported as lasting between 6 and 7 minutes. It was followed by three strong
Tsunami
The tsunami triggered by the earthquake affected the Mexican Pacific coast for more than 500 km along the shores of Oaxaca, Guerrero and Chiapas.[4] The maximum wave height has been estimated as 18.5 m, based on records of inundation and current elevations.[5]
Damage
The earthquake caused damage to buildings in
Future earthquake hazard
The rupture behaviour of the subduction interface in the area of the 1787 earthquake involves occasional very large earthquakes, such as that in 1787, with smaller (M7) earthquakes rupturing just part of the plate boundary during the intervening period. Similar behaviour has been observed along the Colombia-Ecuador subduction zone, with three M7 earthquakes since the M8.8 1906 Ecuador–Colombia earthquake rupturing just part of the same area that slipped in that great earthquake.[3]
See also
- List of earthquakes in Mexico
- List of historical earthquakes
- List of historical tsunamis
References
- ^ doi:10.7289/V5TD9V7K. Retrieved 26 July 2022.
- . Retrieved 30 December 2011.
- ^ doi:10.1785/0120080201. Archived from the original(PDF) on 2016-03-04. Retrieved 2015-05-31.
- Bibcode:2013AGUSMNH41A..03R.
- S2CID 128748891.
Further reading
- Ramírez-Herrera, M.; Corona, N.; Cerny, J.; Castillo-Aja, R.; Melgar, D.; Lagos, M.; Goguitchaichvili, A.; Machain, M.; Vazquez-Caamal, M.; Ortuño, M.; Caballero, M.; Solano-Hernandez, E.; Ruiz-Fernández, A. (2020). "Sand deposits reveal great earthquakes and tsunamis at Mexican Pacific Coast". Scientific Reports. 10 (1): 11452. PMID 32651547.