This list of earthquakes in Ecuador is a list of notable earthquakes that have affected Ecuador in recorded history.
The active tectonics of Ecuador is dominated by the effects of the subduction of the Nazca Plate beneath the South American Plate. 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 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. [1] 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 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. [2]
Earthquakes that affect Ecuador can be divided into those that result from movement on the subduction interface along the plate boundary, those that result from deformation within the South American and Nazca Plates and those that are associated with active volcanoes.
Megathrust events along the subduction interface generate the largest earthquakes, often triggering destructive tsunamis, such as the 1906 Ecuador–Colombia earthquake.
The most damaging earthquakes to affect Ecuador are those associated with faulting within the South American Plate, such as the 1949 Ambato earthquake.
Earthquakes within the downgoing Nazca Plate, such as the Mw 7.1 event of August 2010, are generally too deep to cause significant damage in Ecuador although they are felt over a wide area. [3]
Swarms of relatively small earthquakes are commonly associated with volcanic activity, such as the Quito swarm in 1998-1999 related to the Guagua Pichincha volcano. [4]
Magnitudes - Mw Moment magnitude scale, ML Richter magnitude scale, Ms Surface wave magnitude
The San Andreas Fault is a continental right-lateral strike-slip transform fault that extends roughly 1,200 kilometers (750 mi) through the U.S. state of California. It forms part of the tectonic boundary between the Pacific Plate and the North American Plate. Traditionally, for scientific purposes, the fault has been classified into three main segments, each with different characteristics and a different degree of earthquake risk. The average slip rate along the entire fault ranges from 20 to 35 mm per year.
The Ring of Fire is a tectonic belt of volcanoes and earthquakes.
The North American Plate is a tectonic plate containing most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of 76 million km2 (29 million sq mi), it is the Earth's second largest tectonic plate, behind the Pacific Plate.
The Nazca Plate or Nasca Plate, named after the Nazca region of southern Peru, is an oceanic tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru–Chile Trench, of the Nazca Plate under the South American Plate is largely responsible for the Andean orogeny. The Nazca Plate is bounded on the west by the Pacific Plate and to the south by the Antarctic Plate through the East Pacific Rise and the Chile Rise respectively. The movement of the Nazca Plate over several hotspots has created some volcanic islands as well as east–west running seamount chains that subduct under South America. Nazca is a relatively young plate both in terms of the age of its rocks and its existence as an independent plate having been formed from the break-up of the Farallon Plate about 23 million years ago. The oldest rocks of the plate are about 50 million years old.
The Carnegie Ridge is an aseismic ridge on the Nazca Plate that is being subducted beneath the South American Plate. The ridge is thought to be a result of the passage of the Nazca Plate over the Galapagos hotspot. It is named for the research vessel Carnegie, which discovered it in 1929.
The Andean Volcanic Belt is a major volcanic belt along the Andean cordillera in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru. It is formed as a result of subduction of the Nazca Plate and Antarctic Plate underneath the South American Plate. The belt is subdivided into four main volcanic zones which are separated by volcanic gaps. The volcanoes of the belt are diverse in terms of activity style, products, and morphology. While some differences can be explained by which volcanic zone a volcano belongs to, there are significant differences within volcanic zones and even between neighboring volcanoes. Despite being a type location for calc-alkalic and subduction volcanism, the Andean Volcanic Belt has a broad range of volcano-tectonic settings, as it has rift systems and extensional zones, transpressional faults, subduction of mid-ocean ridges and seamount chains as well as a large range of crustal thicknesses and magma ascent paths and different amounts of crustal assimilations.
The 1906 Ecuador–Colombia earthquake occurred at 10:36:10 (UTC+5) on Wednesday January 31, 1906 off the coast of Ecuador, near Esmeraldas. The earthquake had a moment magnitude of 8.8 and triggered a destructive tsunami that caused at least 500 casualties on the coast of Colombia.
The 1932 Ierissos earthquake occurred at 19:20 on 26 September. It caused severe damage in Ierissos, Greece and the surrounding part of the Chalkidiki peninsula, with 161–491 casualties reported.
The 1949 Ambato earthquake was the deadliest earthquake in the Western Hemisphere in five years. On August 5, 1949, it struck Ecuador's Tungurahua Province southeast of its capital Ambato and killed 5,050 people. Measuring 6.4 on the Ms scale, it originated from a hypocenter 15 km beneath the surface. The nearby villages of Guano, Patate, Pelileo, and Pillaro were destroyed, and the city of Ambato suffered heavy damage. The earthquake flattened buildings and subsequent landslides caused damage throughout the Tungurahua, Chimborazo, and Cotopaxi Provinces. It disrupted water mains and communication lines and opened a fissure into which the small town of Libertad sank. Moderate shaking from the event extended as far away as Quito and Guayaquil.
The 1797 Riobamba earthquake occurred at 12:30 UTC on 4 February. It devastated the city of Riobamba and many other cities in the Interandean valley, causing between 6,000–40,000 casualties. It is estimated that seismic intensities in the epicentral area reached at least XI (Extreme) on the Mercalli intensity scale, and that the earthquake had a magnitude of 7.6–8.3, the most powerful historical event known in Ecuador. The earthquake was studied by Prussian geographer Alexander von Humboldt, when he visited the area in 1801–1802.
The 1868 Ecuador earthquakes occurred at 19:30 UTC on August 15 and 06:30 UTC on 16 August 1868. They caused severe damage in the northeastern part of Ecuador and in southwestern Colombia. They had an estimated magnitude of 6.3 and 6.7 and together caused up to 70,000 casualties. The earthquake of 15 August occurred near El Ángel, Carchi Province, close to the border with Colombia, while that of August 16 occurred near Ibarra in Imbabura Province. Reports of these earthquakes are often confused with the effects of the earthquake of 13 August at Arica.
The 1998 Bahía de Caráquez earthquake occurred on August 4 at 13:59 local time with a magnitude Mw 7.2. The epicenter was located at 10 km north of Bahía de Caráquez, about 190 km NNW of Guayaquil, and about 215 km W of Quito, Ecuador. The intensity in Bahía de Caráquez reached MM VIII. In Bahía de Caráquez, electricity, telephone, and water services disrupted, and many buildings were damaged. It was felt strongly in Guayaquil and Quito and could be felt in much of Ecuador and in Cali, Colombia. An Mw 5.4 foreshock occurred 1 hour and 24 minutes before the main shock and hence alerted many people. The Nazca Plate is subducting beneath the South American Plate near the Ecuadorian coast. This earthquake was a shallow thrust earthquake in this subduction zone.
The 1953 Tumbes earthquake occurred on December 12 at 12:31:29 local time near the border between Peru and Ecuador. The shock had a moment magnitude of 7.5, a maximum Mercalli Intensity of VIII (Severe), and occurred in the northwestern offshore area of Tumbes, Peru.
The 1979 Tumaco earthquake occurred at 02:59 local time on 12 December with a moment magnitude of 8.2 and a maximum Mercalli intensity of IX (Violent). The epicenter was just offshore from the border between Ecuador and Colombia, near the port city of Tumaco. It triggered a major tsunami, which was responsible for most of the estimated 300–600 deaths. The hardest hit area was Colombia's Nariño Department.
An earthquake measuring Mw 8.0 struck Peru and the surrounding areas on 26 May 2019 at 02:41 local time. It had a maximum perceived intensity of VII on the Modified Mercalli intensity scale in the towns of Yurimaguas and Lagunas. Two people died and a further 30 were injured. It was the strongest earthquake in 2019 by magnitude.
The 1942 Ecuador earthquake or the Guayaquil earthquake occurred on 13 May at 21:13 local time with a moment magnitude of Mw 7.9. The temblor struck the coastal (Esmeraldas) region of Manabí Province, Ecuador. It caused damage mainly to cities including Guayaquil, Portoviejo and Guaranda. More than 300 people were killed and the total cost of damage was about US$2.5 million. Ecuador's largest city Guayaquil was the most affected despite the significant distantce from the epicenter. Many reinforced concrete structures in a particular area in the city were completely destroyed, contributing to fatalities.
An earthquake occurred off the coast of the Alaska Peninsula on July 28, 2021, at 10:15 p.m. local time. The large megathrust earthquake had a moment magnitude of 8.2 according to the United States Geological Survey (USGS). A tsunami warning was issued by the National Oceanic and Atmospheric Administration (NOAA) but later cancelled. The mainshock was followed by a number of aftershocks, including three that were of magnitude 5.9, 6.1 and 6.9 respectively.
The 1950 Calama earthquake occurred near the Argentina–Chile border with an epicenter near Calama, Chile in the Atacama Desert on December 9. The event had a hypocenter depth of 113.9 km, beneath the Caichinque volcanic complex. It measured magnitude Mw 8.2 on the moment magnitude scale, making it the largest intermediate depth earthquake ever recorded on Chilean soil. One person was killed and an unspecified number of people were injured in Calama.
The 1657 Concepción earthquake occurred on March 15 at 20:00 local time off the coast of Concepción, Biobío Region in the Spanish Empire. The earthquake caused severe damage along the coast, and generated a large tsunami in the Bay of Concepción. At least 40 people were killed, the majority due to drowning from the tsunami. The town of Concepción was the hardest hit, with the earthquake and tsunami totally destroying it.
A strong earthquake struck southern Ecuador on 18 March 2023. It measured 6.8 on the moment magnitude scale, and struck with a hypocenter 68.0 km (42.3 mi) deep. The epicenter was located in the Gulf of Guayaquil, off the coast of Balao Canton and about 80 kilometres (50 mi) south of Guayaquil. There was major damage, 446 injuries and 18 fatalities in Ecuador's El Oro, Azuay and Guayas provinces. Two additional fatalities and dozens of injuries were reported in Peru.