The 2017 Chiapas earthquake struck at 23:49 CDT on 7 September (local time; 04:49 on the 8th UTC) in the

Gulf of Tehuantepec Gulf of Tehuantepec () is a large body of water on the Pacific coast of the Isthmus of Tehuantepec, southeastern Mexico, at . Many (but not all) Pacific hurricanes form in or near this body of water. A strong, gale-force wind called the Tehu ...

off the southern coast of

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 ...

near the state of Chiapas, approximately southwest of

Pijijiapan Pijijiapan is a town and municipality in the Mexican state of Chiapas, on the coast of the Pacific Ocean about midway between the border with the state of Oaxaca and the international frontier with Guatemala. As of 2010, the municipality had a ...

(alternately, south-southwest of Tres Picos), with a

Mercalli intensity The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the eff ...

of IX (''Violent''). The

moment magnitude 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 ...

was estimated to be . The earthquake caused all of

Mexico City Mexico City ( es, link=no, Ciudad de México, ; abbr.: CDMX; Nahuatl: ''Altepetl Mexico'') is the capital city, capital and primate city, largest city of Mexico, and the List of North American cities by population, most populous city in North Amer ...

to tremble, prompting people to evacuate after the early warning system was triggered. It also generated a

tsunami A tsunami ( ; from ja, 津波, lit=harbour wave, ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater exp ...

with waves above tide level; and tsunami alerts were issued for surrounding areas. Mexico's president called it the strongest earthquake recorded in the country in a century. It was also the second strongest recorded in the country's history, behind the magnitude 8.6 earthquake in 1787, and the largest recorded globally in 2017.

Tectonic setting

The

lies above the

convergent boundary A convergent boundary (also known as a destructive boundary) is an area on Earth where two or more lithospheric plates collide. One plate eventually slides beneath the other, a process known as subduction. The subduction zone can be defined by a ...

where the

Cocos Plate The Cocos Plate is a young oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it. The Cocos Plate was created approximately 23 million years ago when the Farallon Plate ...

is being

subducted Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...

below the

North American Plate The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Pacif ...

at a rate of 6.4 cm/yr (2.5 in/yr).

Background

On 6 September, several earthquake alarms in Mexico City were mistakenly activated, leading to the evacuation of buildings. The incident prompted a review of the system.

Earthquake

According to the National Seismological Service (SSN) of Mexico, 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 ...

was located in the Gulf of Tehuantepec, about southeast of

Tonalá, Chiapas Tonalá is one of the 119 municipalities of Chiapas, in southern Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It i ...

. The

United States Geological Survey The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...

(USGS) reported that the epicenter was about southwest of

, Chiapas. The

hypocenter In seismology, a hypocenter or hypocentre () is the point of origin of an earthquake or a subsurface nuclear explosion. A synonym is the focus of an earthquake. Earthquakes An earthquake's hypocenter is the position where the strain energy ...

was about underground, deeper than usual for a relatively new subduction zone. The SSN reported a measurement of M 8.2, while the USGS also reported a M 8.2 earthquake after correcting an earlier estimate of M 8.0. The earthquake was a result of normal faulting within the Cocos Plate with a displacement of up to . The entire thickness of the lithosphere of the Cocos Plate ruptured during the earthquake. The earthquake is the most powerful to be measured in Mexico since the

1985 Mexico City earthquake The 1985 Mexico City earthquake struck in the early morning of 19 September at 07:17:50 (CST) with a moment magnitude of 8.0 and a maximal Mercalli intensity of IX (''Violent''). The event caused serious damage to the Greater Mexico City area ...

, and is comparable to the

1932 Jalisco earthquakes The 1932 Jalisco earthquakes began on June 3 at 10:36 UTC with a megathrust event that registered 8.1 on the moment magnitude scale. With a maximum perceived intensity of X (''Extreme'') on the Mercalli intensity scale, at least 400 deaths were ...

. Mexican President

Enrique Peña Nieto Enrique Peña Nieto (; born 20 July 1966), commonly referred to by his initials EPN, is a Mexican politician who served as the 64th president of Mexico from 1 December 2012 to 30 November 2018. A member of the Institutional Revolutionary Party ...

called the earthquake the "largest in at least a century" and said that it was felt by 50 million people. Geophysicists at the National Autonomous University of Mexico speculated that the earthquake relieved stored pressure in the "Tehuantepec gap", making future earthquakes in the region less likely.

Tsunami

with waves of and higher was generated by the earthquake and was recorded at

Salina Cruz Salina Cruz is a major seaport on the Pacific coast of the Mexican state of Oaxaca. It is the state's third-largest city and is the municipal seat of the municipality of the same name. It is part of the Tehuantepec District in the west of the ...

; A tsunami wave of was reported in Chiapas. The

Pacific Tsunami Warning Center The Pacific Tsunami Warning Center (PTWC) is one of two tsunami warning centers that are operated by NOAA in the United States. Headquartered on Ford Island, HI, the PTWC is part of an international tsunami warning system (TWS) program and s ...

issued a warning for the entire Pacific coast of

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

, also extending south to

Ecuador Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ' ...

Aftershocks

In the hour following the earthquake, at least 12 aftershocks were recorded by the USGS. As of 00:30 September 14 ( UTC Time), the National Seismological Service (SSN) has recorded at least 1,806 aftershocks, of up to a magnitude of 6.1.

Damage and aftermath

Within Chiapas, an estimated 1.5 million people were affected by the earthquake, with 41,000 homes damaged. Jose Calzada,

Minister of Agriculture An agriculture ministry (also called an) agriculture department, agriculture board, agriculture council, or agriculture agency, or ministry of rural development) is a ministry charged with agriculture. The ministry is often headed by a minister ...

, reported that at least 98 people had died in the earthquake, including 78 in

Oaxaca Oaxaca ( , also , , from nci, Huāxyacac ), officially the Free and Sovereign State of Oaxaca ( es, Estado Libre y Soberano de Oaxaca), is one of the 32 states that compose the political divisions of Mexico, Federative Entities of Mexico. It is ...

, 16 in Chiapas and 4 in

Tabasco Tabasco (), officially the Free and Sovereign State of Tabasco ( es, Estado Libre y Soberano de Tabasco), is one of the 32 Federal Entities of Mexico. It is divided into 17 municipalities and its capital city is Villahermosa. It is located in ...

. The

Secretariat of the Interior The Mexican Secretariat for Home Affairs ( es, Secretaría de Gobernación, SEGOB, lit=Secretariat for Governance) is the public department concerned with the country's domestic affairs, the presenting of the president's bills to Congress, their ...

declared a state of emergency for 122 municipalities in Chiapas, and the

Mexican Army The Mexican Army ( es, Ejército Mexicano) is the combined land and air branch and is the largest part of the Mexican Armed Forces; it is also known as the National Defense Army. The Army is under the authority of the Secretariat of National ...

was deployed to aid in disaster relief. Schools were closed on 8 September in 11 states for safety inspections. Damage in

Veracruz Veracruz (), formally Veracruz de Ignacio de la Llave (), officially the Free and Sovereign State of Veracruz de Ignacio de la Llave ( es, Estado Libre y Soberano de Veracruz de Ignacio de la Llave), is one of the 31 states which, along with Me ...

was reported, meanwhile the state is expecting the arrival of Hurricane Katia on 9 September. Hurricane Max made landfall in

Guerrero Guerrero is one of the 32 states that comprise the 32 Federal Entities of Mexico. It is divided in 81 municipalities and its capital city is Chilpancingo and its largest city is Acapulcocopied from article, GuerreroAs of 2020, Guerrero the pop ...

state on 14 September, near the earthquake-stricken region. Buildings in

Juchitán de Zaragoza Juchitán de Zaragoza (; Spanish name; Isthmus Zapotec: ''Xabizende'' ) is an indigenous town in the southeast of the Mexican state of Oaxaca. It is part of the Juchitán District in the west of the Istmo de Tehuantepec region. With a 2005 censu ...

, closest to the epicenter, were "reduced to rubble" according to reports from the town's mayor. The earthquake also caused buildings to shake and sway in

, while also knocking out electricity for 1.8 million people. There were reports of glass shattered at Mexico City International Airport. An highway bridge under construction near Mexico City's new international airport collapsed due to the shaking. The epicenter was near Mexico's border with Guatemala, where the quake was felt in

Guatemala City Guatemala City ( es, Ciudad de Guatemala), known locally as Guatemala or Guate, is the capital and largest city of Guatemala, and the most populous urban area in Central America. The city is located in the south-central part of the country, ne ...

, and infrastructure damage was reported by CONRED in the nation's south-west. President

Jimmy Morales Jimmy Morales (born James Ernesto Morales Cabrera, ; 18 March 1969) is a Guatemalan politician, actor and comedian. From 2016 to 2020, he served as the 50th president of Guatemala. Early and personal life Morales was born in Guatemala City ...

stated that one Guatemalan was killed. File:Enrique Peña Nieto y Alejandro Murat Hinojosa visitan una zona afectada por el sismo del 7 de septiembre1.jpg, President

inspecting damage to a home in Juchitán, Oaxaca File:Centro de acopio - Terremoto de Chiapas de 2017.jpg, Collection Center for the victims of the earthquake, Mexico City City Hall

Response

On 11 September, Mexico recalled its aid to the United States, offered in the aftermath of Hurricane Harvey, to focus on earthquake recovery. United States President

Donald Trump Donald John Trump (born June 14, 1946) is an American politician, media personality, and businessman who served as the 45th president of the United States from 2017 to 2021. Trump graduated from the Wharton School of the University of P ...

called Mexican President

on 14 September, a week after the earthquake, to express his condolences. Three years after the earthquake, Governor Alejandro Murat reported that 60,000 homes have been rebuilt, but that many others still have not been. He reported that sixty health centers have been reconstructed, and in 2020 they plan to rebuild 2,000 schools.

References

External links

M=6.1 Mexican aftershock strongly promoted by M=8.1 Chiapas mainshock
– Temblor, Inc. * * {{DEFAULTSORT:Chiapas earthquake, 2017 2017 earthquakes 2017 in Guatemala Earthquakes in Guatemala

2017 File:2017 Events Collage V2.png, From top left, clockwise: The War Against ISIS at the Battle of Mosul (2016-2017); aftermath of the Manchester Arena bombing; The Solar eclipse of August 21, 2017 ("Great American Eclipse"); North Korea tests a s ...

2017 earthquake 2017 earthquake September 2017 events in Mexico Megathrust earthquakes in Mexico 2017 disasters in Mexico