The place where the earthquake occurred is a seismically active area, where 3 plates meet, the North American plate to the Northeast, the Cocos plate and the Rivera plate to the South. Both the Cocos and Rivera plates are slowly sinking below the North American plate by 2 centimeters (0,79 inches) per year, relative to the rapid movement of the Cocos Plate with that of North America which moves 4 centimeters (1.8 in) per year.[3]
The earthquake occurred due to thrust fault, between the Cocos plate and North America plate. This earthquake is not related to that of 1985, 1995 and 2003. According to the United States Geological Survey, earthquakes of this size typically rupture in an area measuring 90 km (56 mi) x 40 km (25 mi). Most of the co-seismic slip occurred directly below ground rather than offshore with a maximum displacement of 1.2 m (3 ft 11 in).
The earthquake coincides with the 37th anniversary of the 1985 earthquake that killed 10,000 people and the 5th anniversary of the 2017 earthquake, an hour before the national drill of 19S had occurred in case of earthquakes.[4]
Over 2,000 aftershocks have been reported[8][9][10] including the 849 aftershocks of September 19[11] the largest being 5.2[12] the largest of 5.9 to a depth of 54.5 km (33.9 mi)[13] occurred on September 20.
An aftershock of 6.8 Mw was felt at 01:16 on September 22 to a depth of 20.7 km (12.9 mi)[14] There were a total of 2 deaths, one from falling down the stairs and the other from a heart attack.[15][16]
Impact of the earthquake
In Colima, two people died and nine wounded in total, 2,790 houses in 10 municipalities were affected.[17] 20 buildings, two temples and seven medical facilities were affected, while five bridges and eight roads were destroyed. In Manzanillo a person died[18] when a fence of a shopping center fell the second victim died when a Gym partially collapsed in another shopping center.[19] An explosion of a gas tank in Tecomán caused four injuries, two of them children.[20] Just as landslides were reported.[21][22]
In Michoacán, 3,161 houses and 89 schools were affected in Coalcomán, Chiniculla, Coahuayana and Aquila. 21 hospitals were also affected and two of them were evicted. there was structural damage to three churches, and several buildings, seven bridges and lines of communication and a collapsing road, were also affected. In Coahuayana there were 26 injured and a gas explosion.[23]
In Guadalajara, Jalisco a man's arm was amputated in an elevator accident. Like the fall of rubble from the temple of La Merced and San Agustín, in Puerto Vallarta there was collapse of roofs and glass and apartment buildings cracks would be reported.[24]
In Tepic, Nayarit the towers of the Tepic Cathedral were heavy damaged as well as falling debris in the subdivision of Villa de Arana a hospital and houses were damaged, in Ixtlán del Río a fence of a primary school collapsed and a financial building was damaged, Stores and objects were damaged in Bahía de Banderas, in Compostela an abandoned school cracked open and two people were injured in San Blas one in a motorcycle accident and another in a fall.[25]
In Mexico City, buildings swayed and 21 buildings and others suffered minor and significant damage,[26] that had already suffered in previous earthquakes, 76 schools were reported as damaged and only one received serious damage for which classes were suspended.[27]
