1887 Sonora earthquake
Encyclopedia
The 1887 Sonora earthquake occurred at 22:13 UCT
on 3 May in the Teras mountain range of northwestern Mexico
. It was widely felt, with some damage being recorded up to 200 km from the epicenter
in both Mexico and the United States
. The earthquake had an estimated magnitude
of 7.6 and caused 42 casualties in the town of Bavispe
and 51 overall. It was the only historical earthquake to cause considerable damage in Arizona
.
The 1887 Tombstone Arizona newspapers mentioned lesser quakes (aftershocks) on August 27, 1887 and November 11, 1887.
Basin and Range Province. The western margin of the Sierra Madre Occidental
plateau is formed by a series of west-dipping normal faults, over a distance of at least 300 km. The earthquake occurred within this zone.
construction were also destroyed in Tepic
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
s and caused ground fissures. Moderate to severe damage occurred in northeastern Sonora
, northwestern Chihuahua, southwestern New Mexico
, southeastern Arizona and the westernmost part of Texas
.
from an analysis of an isoseismal map
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.
Coordinated Universal Time
Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose...
on 3 May in the Teras mountain range of northwestern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. It was widely felt, with some damage being recorded up to 200 km from the epicenter
Epicenter
The epicenter or epicentre is the point on the Earth's surface that is directly above the hypocenter or focus, the point where an earthquake or underground explosion originates...
in both Mexico and the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. The earthquake had an estimated magnitude
Moment magnitude scale
The moment magnitude scale is used by seismologists to measure the size of earthquakes in terms of the energy released. The magnitude is based on the seismic moment of the earthquake, which is equal to the rigidity of the Earth multiplied by the average amount of slip on the fault and the size of...
of 7.6 and caused 42 casualties in the town of Bavispe
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...
and 51 overall. It was the only historical earthquake to cause considerable damage in Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
.
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 extensionalExtensional tectonics
Extensional tectonics is concerned with the structures formed, and the tectonic processes associated with, the stretching of the crust or lithosphere.-Deformation styles:...
Basin and Range Province. The western margin of the Sierra Madre Occidental
Sierra Madre Occidental
The Sierra Madre Occidental is a mountain range in western Mexico.-Setting:The range runs north to south, from just south of the Sonora–Arizona border southeast through eastern Sonora, western Chihuahua, Sinaloa, Durango, Zacatecas, Nayarit, Jalisco, Aguascalientes to Guanajuato, where it joins...
plateau is formed by a series of west-dipping normal faults, over a distance of at least 300 km. 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 adobeAdobe
Adobe is a natural building material made from sand, clay, water, and some kind of fibrous or organic material , which the builders shape into bricks using frames and dry in the sun. Adobe buildings are similar to cob and mudbrick buildings. Adobe structures are extremely durable, and account for...
construction were also destroyed in Tepic
Tepic
Tepic is the capital and largest city of the Mexican state of Nayarit.It is located in the central part of the state, at.It stands at an altitude above sea level of some 915 meters, on the banks of the Río Mololoa and the Río Tepic, approximately 225 kilometers north-west of Guadalajara, Jalisco....
and Moctezuma
Moctezuma, Sonora
Moctezuma is a municipio of the Mexican state of Sonora, located in the state's central region. It is also the name of its largest settlement and cabecera municipal .-Area and Population:...
. 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
Landslide
A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...
s and caused ground fissures. Moderate to severe damage occurred in northeastern Sonora
Sonora
Sonora officially Estado Libre y Soberano de Sonora is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided into 72 municipalities; the capital city is Hermosillo....
, northwestern Chihuahua, southwestern New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
, southeastern Arizona and the westernmost part of Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
.
Characteristics
The earthquake was associated with a surface rupture 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 scaleMoment magnitude scale
The moment magnitude scale is used by seismologists to measure the size of earthquakes in terms of the energy released. The magnitude is based on the seismic moment of the earthquake, which is equal to the rigidity of the Earth multiplied by the average amount of slip on the fault and the size of...
from an analysis of an isoseismal map
Isoseismal map
In seismology an isoseismal map is used to show lines of equal felt seismic intensity, generally measured on the Modified Mercalli scale. Such maps help to identify earthquake epicenters, particularly where no instrumental records exist, such as for historical earthquakes...
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.