The 1887 Sonora earthquake occurred at 22:13

UCT The University of Cape Town (UCT) ( af, Universiteit van Kaapstad, xh, Yunibesithi ya yaseKapa) is a public research university in Cape Town, South Africa. Established in 1829 as the South African College, it was granted full university stat ...

on 3 May in the Teras mountain range of northwestern

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

. It was widely felt, with some damage being recorded up to from the

epicenter The epicenter, epicentre () or epicentrum in seismology is the point on the Earth's surface directly above a hypocenter or focus, the point where an earthquake or an underground explosion originates. Surface damage Before the instrumental pe ...

in both Mexico and the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. The earthquake had an estimated

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

of 7.6 and caused 42 casualties in the town of

Bavispe Bavispe is a small town and a municipality in the northeast part of the Mexican state of Sonora. Location The municipality is located in the northeast of the state at . The elevation of the administrative seat is 902 meters above sea level. It ...

and 51 overall. It was the only historical earthquake to cause considerable damage in

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

. The 1887 Tombstone Arizona newspapers mentioned lesser quakes (aftershocks) on August 27, 1887, and November 11, 1887.

Tectonic setting

The earthquake was located near the southern end of the extensional

Basin and Range Province The Basin and Range Province is a vast physiographic region covering much of the inland Western United States and northwestern Mexico. It is defined by unique basin and range topography, characterized by abrupt changes in elevation, alternating ...

. The western margin of the

Sierra Madre Occidental The Sierra Madre Occidental is a major mountain range system of the North American Cordillera, that runs northwest–southeast through northwestern and western Mexico, and along the Gulf of California. The Sierra Madre is part of the American C ...

plateau is formed by a series of west-dipping normal faults, over a distance of at least . The earthquake occurred within this zone.

Damage

Towns near the epicenter suffered significant damage, particularly in Bavispe, where most houses were destroyed and 42 of the town's 700 inhabitants were killed. Houses of

adobe Adobe ( ; ) is a building material made from earth and organic materials. is Spanish for ''mudbrick''. In some English-speaking regions of Spanish heritage, such as the Southwestern United States, the term is used to refer to any kind of e ...

construction were also destroyed in

Tepic Tepic () is the capital and largest city of the western Mexican state of Nayarit, as well as the seat of the Tepic Municipality. Located in the central part of the state, it stands at an altitude of above sea level, on the banks of the Rí ...

and Moctezuma. The houses were roofed with heavy log rafters that were untied to the adobe walls and fell in when the walls collapsed. The earthquake triggered many rockfalls and

landslide Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated grade (slope), slope failures, mudflows, and debris flows. Landslides occur in a variety of ...

s and caused ground fissures. Moderate to severe damage occurred in northeastern

Sonora Sonora (), officially Estado Libre y Soberano de Sonora ( en, Free and Sovereign State of Sonora), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is d ...

, northwestern Chihuahua, southwestern

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ker ...

, southeastern Arizona and the westernmost part of

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

Characteristics

The earthquake was associated with a

surface rupture In seismology, surface rupture (or ground rupture, or ground displacement) is the visible offset of the ground surface when an earthquake rupture along a fault affects the Earth's surface. Surface rupture is opposed by buried rupture, where th ...

consisting of three segments with a combined length of 101.8 km, the longest normal fault rupture recorded for an earthquake in historic times. The three faults that ruptured were the Pitáycachi, Teras, and Otates faults from north to south. The magnitude of the event has been estimated as 7.6 on the

moment magnitude scale The moment magnitude scale (MMS; denoted explicitly with or Mw, and generally implied with use of a single M for magnitude) is a measure of an earthquake's magnitude ("size" or strength) based on its seismic moment. It was defined in a 1979 pape ...

from an analysis of an

isoseismal map In seismology, an isoseismal map is used to show lines of equally felt seismic intensity, generally measured on the Modified Mercalli scale. Such maps help to identify earthquake epicenters, particularly where no instrumental records exist, such a ...

drawn up for this event, following a re-evaluation of earlier estimates of felt intensity. There was a prolonged sequence of aftershocks that are interpreted to continue to the present. Particularly large aftershocks (about magnitude 5) occurred on 26 May 1907, 17 May 1913 and 18 and 19 December 1923.

Assistance and reporting

The earthquake destroyed most of the adobe houses in Bavispe and killed 42 of the town's 700 residents; Dr.

George E. Goodfellow George Emory Goodfellow (December 23, 1855 – December 7, 1910) was a physician and naturalist in the 19th- and early 20th-century American Old West who developed a reputation as the United States' foremost expert in treating ...

in Tombstone,

Arizona Territory The Territory of Arizona (also known as Arizona Territory) was a territory of the United States that existed from February 24, 1863, until February 14, 1912, when the remaining extent of the territory was admitted to the Union as the state of ...

, loaded his wagon with medical supplies and rode to aid survivors. The townspeople named him ''El Doctor Santo'' (The Holy Doctor), and in recognition of his humanitarian contributions, Mexican President

Porfirio Diaz Porfirio is a given name in Spanish, derived from the Greek Porphyry (''porphyrios'' "purple-clad"). It can refer to: * Porfirio Salinas – Mexican-American artist * Porfirio Armando Betancourt – Honduran football player * Porfirio Barba-Jac ...

presented him with a silver medal that had belonged to Emperor Maximilian and a horse named ''El Rosillo''. Goodfellow noted that it was very difficult to pin down the time of the earthquake due to the absence of time pieces or a nearby railroad, and the primitive living standards of the area's residents. Goodfellow returned twice, the second time in July with Tombstone photographer Camillus Sidney Fly to study and record the effects of the earthquake. He covered over on horseback but mostly on foot through the

Sierra Madre Oriental The Sierra Madre Oriental () is a mountain range in northeastern Mexico. The Sierra Madre Oriental is part of the American Cordillera, a chain of mountain ranges (cordillera) that consists of an almost continuous sequence of mountain ranges that f ...

mountains recording his observations. His report included the first surface rupture map of an earthquake in North America and photographs of the rupture scarp by C.S. Fly. The United States Geological Service praised his "remarkable and creditable" report, describing it as "systematic, conscientious, and thorough." The earthquake was at the time the “longest recorded normal-fault surface rupture in historic time.” His report was later described as an “outstanding study” and a “pioneering achievement”.

References

{{Earthquakes in the United States Sonora Earthquake, 1887 Sonora Earthquake, 1887 Sonora Earthquake, 1887 Natural disasters in the Southwestern United States Earthquakes in Arizona Earthquakes in Mexico May 1887 events Sonora Earthquake, 1887 Sonora Earthquake, 1887

Tectonic setting

Damage

Characteristics

Assistance and reporting

See also

References