Earthquake in Mexico in 1787
| Earthquake in Mexico | |||
|---|---|---|---|
|
|||
| date | March 28, 1787 | ||
| Time | 17:30 UTC | ||
| epicenter | 16 ° 30 ′ 0 ″ N , 98 ° 30 ′ 0 ″ W | ||
| country | Mexico | ||
| Tsunami | Yes | ||
| dead | 11 dead in the tsunami, unknown in total | ||
The 1787 Mexico earthquake , also known as the San Sixto earthquake , occurred on March 28, 1787 at 11:30 am local time (17:30 UTC). It caused a major tsunami that inundated the coast of the states of Guerrero and Oaxaca in southwestern Mexico. With an estimated magnitude of 8.6 M W and 8.3 M S , it was stronger than any earthquake recorded with seismographs in Mexico.
Tectonic overview
Southwest Mexico is located on a subduction zone where the coconut plate pushes under the North American plate at a rate of 6.4 cm / year . The inclination of the subducting plate is about 15 °, as defined by focal surface solution and earthquake hypocenters . Seismicity in this area is characterized by regular megathrust earthquakes along the converging plate boundaries .
earthquake
The earthquake was reported to last for 6-7 minutes. It was felt over a wide area from Valladolid to Tehuantepec along the coast and inland to Tulancingo . The magnitude of this earthquake was estimated from contemporary reports on the intensity. If one assumes that - as is usual with earthquakes in Mexico - the fracture zone is identical to the regions in which intensities of VIII or higher (according to the modified Mercalli scale ) were reported, the length of the fracture zone can be estimated at 450 kilometers. That's at least three times as long as usual in this region observed earthquake and leaves on an earthquake of magnitude 8.6 M W close. No earthquake as strong as this has been recorded in Mexico in the history of seismographs .
This was followed by three strong aftershocks on March 29, March 30 and April 3, the magnitudes of which are estimated to be 7 or more, based on the reported intensities in Oaxaca de Juárez .
Tsunami
The tsunami that was triggered by the earthquake hit the Mexican Pacific coast for more than 500 km on the shores of the states of Oaxaca , Guerrero and Chiapas . The maximum wave height was estimated to be 18.5 m based on records of flooding and wave heights.
Damage
The earthquake caused damage to buildings in Mexico City and many buildings in Oaxaca de Juarez were destroyed. Three churches in Teuchitlán were destroyed.
Individual evidence
- ^ Paula Dunbar: Significant Earthquake. Retrieved September 11, 2017 .
- ↑ Short Note Evidence for Great Tsunamigenic Earthquakes (M 8.6) along the Mexican Subduction Zone. (PDF) Retrieved September 11, 2017 .
- ^ Francisco J. Núñez-Cornú, Modesto Ortiz, John J. Sánchez: The great 1787 Mexican tsunami . In: Natural Hazards . tape 47 , no. 3 , December 2008, ISSN 0921-030X , p. 569-576 , doi : 10.1007 / s11069-008-9239-1 .