.jpg) A partially destroyed church in Saltillo Lafragua | |
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| UTC time | 1920-01-04 04:22:16 |
|---|---|
| ISC event | 912397 |
| USGS-ANSS | ComCat |
| Local date | 3 January 1920 |
| Local time | 22:25 CST |
| Magnitude | Mw 6.3–6.4 |
| Depth | 15 kilometres (9.3 mi) |
| Epicenter | 19°16′N 97°05′W / 19.27°N 97.08°W[1] |
| Type | Normal |
| Areas affected | |
| Max. intensity | MMI XII (Extreme) |
| Aftershocks | continued until April 1920 |
| Casualties | 648–4,000 killed |
A moment magnitude 6.3–6.4 earthquake affected the Trans-Mexican Volcanic Belt in the states of Puebla and Veracruz, Mexico on 3 January 1920 at 22:25 CST.[2] A maximum Modified Mercalli intensity of XI–XII (Extreme) was assigned in the epicenter, between Chilchotla and Patlanalán. The earthquake killed between 648 and 4,000 people; many deaths were attributed to mudslides that swept through several settlements along the Huitzilapa and Pescado rivers. Many buildings, especially the masonry kind, were badly damaged or totally ruined. The towns of Patlanalá, Barranca Grande, Cosautlán, Quimixtlán and Teocelo were severely affected. Wooden jacales generally performed well during the earthquake but some were destroyed. The total cost of damage was estimated at US$25 million.
The volcanic belt undergoes crustal extension which causes normal faults to form in response to the tectonic deformation. These faults can produce earthquakes and pose a threat to highly populated towns due to their close proximity. However, they are rare with return periods of several thousand years. A 2008 hazard zoning considered the area moderately at risk of earthquakes while a 2017 research suggests that risk is higher. The 1920 earthquake may have been caused by rupture along a normal fault within the belt. After the earthquake, a seismograph was deployed in Xalapa to record the aftershocks. The yielded data from the seismograph suggested the mainshock originated within the Earth's crust.
The Veracruz government immediately provided assistance and established communication services. Governor Cándido Aguilar formed a disaster relief board and travelled to several towns to participate in distributing resources. The devastated towns of Xalapa, Coatepec, Cosautlán, Coscomatepec, Patlanalá, Quimixtlán, Huatusco and Ayahualco were given funds for reconstruction. The Bishop Rafael Guízar y Valencia assisted in the relief efforts and donations. Civil society groups and civilians also participated in relief efforts through joining relief committees and raising funds. Some local newspapers overdramatized their reports and falsely claimed that volcanoes in the area were erupting. Others organised fundraising or promoted Guízar's fundraising efforts and eventually raised over Mex$300,000. The El Salvador and Honduras government, and Pope Benedict XV, also contributed monetary aid.