A strong earthquake struck southern

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

on 18 March 2023. It measured 6.8 on the

moment magnitude scale The moment magnitude scale (MMS; denoted explicitly with or Mwg, 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. was defined in a 1979 paper ...

, and struck with a

hypocenter A hypocenter or hypocentre (), also called ground zero or surface zero, is the point on the Earth's surface directly below a nuclear explosion, meteor air burst, or other mid-air explosion. In seismology, the hypocenter of an earthquake is its ...

deep. The epicenter was located in the

Gulf of Guayaquil The Gulf of Guayaquil is a large body of water of the Pacific Ocean in western South America. Its northern limit is the city of Santa Elena, Ecuador, Santa Elena, in Ecuador, and its southern limit is Cabo Blanco, Peru, Cabo Blanco, in Peru. The ...

, off the coast of Balao Canton and about south of

Guayaquil Guayaquil (), officially Santiago de Guayaquil, is the largest city in Ecuador and also the nation's economic capital and main port. The city is the capital (political), capital of Guayas Province and the seat of Guayaquil Canton. The city is ...

. There was major damage, 446 injuries and 18 fatalities in Ecuador's El Oro,

Azuay Azuay (, ), Province of Azuay is a province of Ecuador, created on 25 June 1824. It encompasses an area of . Its capital and largest city is Cuenca. It is located in the south center of Ecuador in the highlands. Its mountains reach above sea le ...

and Guayas provinces. Two additional fatalities and dozens of injuries were reported in

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

Tectonic setting

The active

tectonics Tectonics ( via Latin ) are the processes that result in the structure and properties of the Earth's crust and its evolution through time. The field of ''planetary tectonics'' extends the concept to other planets and moons. These processes ...

of Ecuador is dominated by the effects of the

subduction Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second p ...

of the

Nazca plate The Nazca plate or Nasca plate, named after the Nazca region of southern Peru, is an oceanic list of tectonic plates, tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru– ...

beneath the

South American plate The South American plate is a major tectonic plate which includes the continent of South America as well as a sizable region of the Atlantic Ocean seabed extending eastward to the African plate, with which it forms the southern part of the Mid ...

. Ecuador lies within the Northern Volcanic Zone where the subduction zone is moving at a rate of 7 cm/yr to the east-northeast, significantly oblique to the trend of this segment of the Andes. The subduction zone has an overall dip of 25–30°, but varies rapidly along strike due to the effects of subduction of the

Carnegie Ridge The Carnegie Ridge is an aseismic ridge on the Nazca plate that is being Subduction, subducted beneath the South American plate. The ridge is thought to be a result of the passage of the Nazca Plate over the Galápagos hotspot. It is named for th ...

. The Carnegie Ridge is an oceanic plateau that formed as the Nazca plate passed over the Galapagos hotspot. The plate interface above the subducted part of the ridge has a shallower dip than the area to both north and south, the boundaries interpreted to consist of two large tears in the downgoing Nazca plate. The northern part of Ecuador overlies the subducted part of the Carnegie Ridge and is an area where the Nazca plate is interpreted to be strongly coupled to the South American plate, causing an unusually large degree of intraplate deformation. The main

active fault An active fault is a fault that is likely to become the source of another earthquake sometime in the future. Geologists commonly consider faults to be active if there has been movement observed or evidence of seismic activity during the last 10,0 ...

zones of Ecuador are SSW-NNE trending dextral strike-slip faults running parallel to the main subdivisions of the Andes, two major SW-NE dextral strike-slip zones, the Pallatanga and Chingual faults, and north–south trending reverse faults such as the Quito fault. Large earthquakes are common in Ecuador. In the past century, 32 earthquakes M6.0 and larger have occurred within 250 km of this event. On 16 April 2016, a magnitude 7.8 earthquake on the subduction zone interface ~350 km north of the 2023 event resulted in over 600 deaths and over 27,000 injuries.

Earthquake

The earthquake had a magnitude of 6.8 and estimated maximum MMI of VII (''Very strong''), according to the

United States Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...

(USGS). The European-Mediterranean Seismological Centre reported a magnitude of 6.7. According to the USGS

PAGER A pager, also known as a beeper or bleeper, is a Wireless communication, wireless telecommunications device that receives and displays Alphanumericals, alphanumeric or voice messages. One-way pagers can only receive messages, while response p ...

service, shaking intensity V–VII (''Moderate''–''Very Strong'') was felt by 8.41 million people, nearly half of

's population, including intensity VI (''Strong'') in

. It was felt in 13 of the country's 24 provinces. The country's Geophysical Institute of the National Polytechnic School reported the EMS-98 intensity was V–VI (''Strong''–''Slightly damaging'') in southern Guayas Province. Intensity V–VI was also observed in Machala, Santa Rosa and Huaquillas. The earthquake occurred as the result of oblique-slip faulting at an intermediate depth near the subduction interface of the

Nazca Nazca (; sometimes spelled Nasca; possibly from ) is a city and system of valleys on the southern coast of Peru. The city of Nazca is the largest in the Nazca Province. The name is derived from the Nazca culture, which flourished in the area be ...

and

s. Its faulting mechanism and depth suggest the event occurred within the subducted

lithosphere A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the lithospheric mantle, the topmost portion of the upper mantle that behaves elastically on time ...

of the Nazca plate. Focal mechanism solutions indicate that rupture occurred on either a near vertically dipping fault striking to the southeast or a moderately dipping fault striking to the southwest. At the location of the earthquake, the Nazca plate moves to the east relative to the South American plate at a velocity of about per year. Earthquakes in Ecuador and most of western

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

are caused by the strains generated by ongoing subduction. Events such as this are called intermediate-depth earthquakes, occurring at depth. Intermediate-depth earthquakes represent deformation within subducted slabs rather than at the shallow plate interface between subducting and overriding tectonic plates. Typically less damaging on the ground surface above their epicenter than is the case with similar-magnitude shallow-focus earthquakes, but can still be destructive. Large intermediate-depth earthquakes may be felt at large distances from their epicenters.

Impact

Ecuador

The quake was felt in 13 of the country's 24 provinces. A total of 96 houses collapsed and 318 houses, 148 schools, 55 health facilities, 54 public infrastructure, 56 private infrastructure, and one bridge were damaged. At least 494 people were injured across the country.

El Oro

In El Oro, 40 houses collapsed and 12 people – including an infant and five members of a single family – were killed, mostly in the city of

Machala Machala () is a city in south-west Ecuador. It is the capital of the El Oro Province, and is located near the Gulf of Guayaquil on fertility (soil), fertile lowlands. Machala has a population of 288,072 (2022 census); it is the sixth-biggest city ...

. Three people died when a tower collapsed. In

Puerto Bolívar Puerto Bolívar is an Parishes of Ecuador, urban parish and port city, part of the municipality of Machala, El Oro Province, Ecuador. Puerto Bolívar is one of the world's largest shipment points for bananas, most of them destined for Europe; ab ...

, a building housing a museum and a restaurant collapsed into the sea. Collapsed buildings in the province trapped many people. One

Peruvian Peruvians (''/peruanas'') are the citizens of Peru. What is now Peru has been inhabited for several millennia by cultures such as the Caral before the Spanish conquest in the 16th century. Peruvian population decreased from an estimated 5–9 ...

resident was among the dead in the province. In the southern parts of some places in the province, telephone lines were downed and power outages occurred.

Guayas

, 6 buildings collapsed and 73 buildings and houses were damaged, glass was broken, some walls collapsed, and stores were closed across the city.

Power outage A power outage, also called a blackout, a power failure, a power blackout, a power loss, a power cut, or a power out is the complete loss of the electrical power network supply to an end user. There are many causes of power failures in an el ...

s affected the city, with the northern and southern sectors had no electricity for as long as seven hours, while in some other areas, electricity was restored after 30 minutes. Three vehicle tunnels in the city were also closed, and one person was injured. One person died in Naranjal. On

Puná Island Puná Island (Spanish: ''Isla Puná''), is an island just off the coast of southern Ecuador at approximately 80 degrees west longitude and 3 degrees south latitude. It is located at the head of the Gulf of Guayaquil, south of the mouth of the ...

, one of the closest areas to the epicenter, 10 houses collapsed.

Azuay

Two people died in Cuenca, the provincial capital, including one person killed when a house façade collapsed onto a car; another two were injured. Two houses were destroyed and another four were damaged in the province.

Peru

In Tumbes, close to

's border with Ecuador, a four-year-old girl was killed when the roof of a house fell, while a teenager was killed after a house collapsed. Another child was injured, and some others due to landslides. Six houses collapsed, and 46 houses, two health facilities and 12 schools were damaged in the region's three provinces. Thirty-nine people were left homeless and another 101 were affected.

Response

The Ecuadorian Secretariat for Risk Management said firefighters were deployed in search and rescue operations. The National Police conducted damage assessments. President Guillermo Lasso urged citizens to remain calm, adding that "Emergency teams are mobilising to offer all their support to those who have been affected." Toppled power lines interrupting communication and electricity services hampered rescue work. Three facilities of Petroecuador suspended operations temporarily. Ecuador's president,

Guillermo Lasso Guillermo Alberto Santiago Lasso Mendoza (; born 16 November 1955) is an Ecuadorian businessman, banker and politician who served as the 47th president of Ecuador from 2021 to 2023. He was the country's first conservative president in nearly tw ...

, visited the affected provinces on 19 March. He said the number of deaths and injuries could rise over the next few hours. Emergency funds for health and housing were opened, and a 60-day

state of emergency A state of emergency is a situation in which a government is empowered to put through policies that it would normally not be permitted to do, for the safety and protection of its citizens. A government can declare such a state before, during, o ...

was declared for the 14 provinces affected by the earthquake. The

Confederation of Indigenous Nationalities of Ecuador The Confederation of Indigenous Nationalities of Ecuador () or, more commonly, CONAIE, is Ecuador's largest indigenous rights organization. The Ecuadorian Indian movement under the leadership of CONAIE is often cited as the best-organized and ...

initiated an aid campaign for those affected. In March 2023, Blanca Sacancela failed to get a debate at the National Assembly regarding her proposal that the assembly's members should give 50% of their salaries to the victims of the recent earthquake.

Notes

References

{{DEFAULTSORT:Guayas earthquake, 2023 2023 earthquakes 2023 disasters in Ecuador 2023 disasters in Peru March 2023 in Ecuador March 2023 in Peru Earthquakes in Ecuador Earthquakes in Peru 2023 earthquake