M 7.6 earthquake just off the Mexican coast. Relatively shallow as well (15 km). And on the anniversary of the catastrophic 1985 Mexico City quake, no less.
The September 19, 2022, M7.6 earthquake near the Pacific Coast of Mexico occurred as the result of shallow thrust faulting. The location, depth, and mechanism of the event are broadly consistent with slip on or near the boundary interface between the subducting Cocos oceanic plate and the North America plate. The broad-scale tectonics of the Pacific Coast of Mexico are controlled by the northeastward subduction of the Cocos plate beneath the North America plate at a rate of approximately 70 mm/yr.
While commonly plotted as points on maps, earthquakes the size of the September 19, 2022, event are more appropriately described as slip over a larger fault area. Earthquakes of this size and mechanism are typically about 90x40 km (length x width).
Earthquakes are a common occurrence along the Middle America subduction zone. In the preceding 50 years, there have been 13 other earthquakes M 6.5 or larger within 250 km of the September 19th event. This includes the 1995 M 8.0 event approximately 125 km to the northwest as well as the 1985 M 8.0 event approximately 80 km to the southeast. Both the 1985 M 8.0 event and a M 7.1 earthquake near Matzaco, Mexico, in 2017 occurred on the date September 19. Despite the coincidence, there is no specific date or time of year when Mexico is statistically more prone to seismic activity.