Historic Earthquakes

Northern Sonora, Mexico
1887 May 03 UTC
Magnitude 7.4

This earthquake occurred in a sparsely settled region of Northern Sonora, Mexico. It caused widespread damage to property, 51 deaths, and many injuries. From Guaymas, Sonora, Mexico to Nogales, Arizona; Benson and Tucson, Arizona; El Paso, Texas; and at towns as far away Albuquerque, New Mexico, water in tanks slopped over, railroad cars were set in motion on tracks, chimneys were thrown down, and buildings were cracked. Other U.S. cities that sustained moderate to heavy damage include; Bisbee, Fairbank, Fort Huachuca, Saint David, San Simon, Solomonville, Tombstone, Tres Alamos, and Wilcox, Arizona; and Deming, Sabinal, and Silver City, New Mexico. Near the epicenter, liquefaction effects induced significant ground failure that led to the collapse of buildings and other structures.

At Tepic, Sonora, a town about 190 kilometers south of Tombstone, Arizona, the walls and roofs of every house were shattered - many of the walls had fallen out, and the roofs had collapsed. The plaza and streets at Tepic were "ripped up" by fissures, some as wide as 15 centimeters, and irrigation ditches around the town were broken. At Moctezuma, about 32 kilometers south of Tepic, the houses were wrecked, and all inhabitants were living outside. At Oputo, about 56 kilometers northeast of Tepic, a church collapsed and killed 40 people who had run there for shelter from the earthquake. American prospectors in that area reported that a ground fissure about 0.8 meters wide was created by the earthquake.

The 76-kilometer-long fault scarp produced by this earthquake is clearly exposed on the east side of the San Bernardino Valley of Northern Sonora, southeast of Douglas, Arizona. The maximum displacement on the Pitaycachi fault is 4.5 to 5.1 meters, and evidence exists for previous ruptures on the fault. A significant region of liquefaction was reported as far as 100 kilometers from the fault, and landslides were observed at farther distances. In late 1972, the 1887 scarp was observed from the air along its total length. This study revealed many additional scarps, previously unmapped, paralleling the main fault trace. These scarps appear to represent active faulting over the previous several thousand years.

Seismic motion was felt from Tolica, Mexico (near Mexico City) on the south to Albuquerque and Santa Fe, New Mexico, on the north; and from Baja California, Mexico, and Yuma, Arizona, on the west to a point 100 kilometers east of El Pasa, Texas, on the east. There also was a report that the earthquake was felt in California. Many aftershocks were observed.

Abridged from Seismicity of the United States, 1568-1989 (Revised), by Carl W. Stover and Jerry L. Coffman, U.S. Geological Survey Professional Paper 1527, United States Government Printing Office, Washington: 1993.