  San Buenaventura San Gabriel San Juan Capistrano San Diego | |
| UTC time | 1812-12-08 15:00:00 |
|---|---|
| USGS-ANSS | ComCat |
| Local date | December 8, 1812 |
| Local time | 07:00 [1] |
| Magnitude | 6.9 Mla [1] 7.5 Mw [2] |
| Type | Unknown |
| Areas affected | Alta California New Spain |
| Total damage | Moderate [3] |
| Max. intensity | MMI IX (Violent) [4][5] |
| Casualties | 40 killed [1] |
The 1812 San Juan Capistrano earthquake, also known simply as the Capistrano earthquake or the Wrightwood earthquake,[6] occurred on December 8 at 15:00 UTC in Alta California. At the time, this was a colonial territory of the Spanish Empire. Damage occurred at several of the missions in the region of Pueblo de Los Ángeles, including Mission San Gabriel Arcángel and Mission San Juan Capistrano, where 40 parishioners were killed during the collapse of a church at an early morning service. Tree ring and paleoseismic evidence show that there is a strong likelihood that the earthquake originated along the Mojave segment of the San Andreas Fault near Wrightwood, but other faults have been suggested as the cause.
Several studies in the 1980s placed the shock along the southern Newport–Inglewood Fault near the zone of highest reported intensity. This fault is near the coast and the most significant damage at the missions, but later work at trench sites along the San Andreas Fault excluded it for this large to very large shock. Dynamic rupture modelling made possible another proposal in the 2010s involving a dual rupture scenario with both the San Andreas and San Jacinto Fault Zones. Each of these studies worked with limited data, and the effects of the shock and various fault rupture details led to Mercalli intensities of VII (Very strong) to IX (Violent) being proposed. Magnitudes from 6.9 Mla on the low end to 7.5 Mw on the high end were also presented.
- ^ a b c Cite error: The named reference
Stoverwas invoked but never defined (see the help page). - ^ Cite error: The named reference
Siehwas invoked but never defined (see the help page). - ^ Cite error: The named reference
NGDCwas invoked but never defined (see the help page). - ^ Cite error: The named reference
Toppozada_1981was invoked but never defined (see the help page). - ^ Cite error: The named reference
NGDCEIDwas invoked but never defined (see the help page). - ^ City of Huntington Beach - City of Huntington Beach Miscellaneous Historical Data