1922 Vallenar earthquake
Encyclopedia
The 1922 Vallenar earthquake was a magnitude
8.5 earthquake
that occurred in the Atacama Region
of Chile
, near the border with Argentina
on November 11, 1922 at 04:32 UTC. It triggered a destructive tsunami that caused significant damage to the coast of Chile and was observed as far away as Australia
.
and South American
tectonic plates
, at a location where they converge
at a rate of seventy millimeters a year.
Chile has been at a convergent plate boundary that generates megathrust earthquake
s since the Paleozoic
(500 million years ago). In historical times the Chilean coast has suffered many megathrust earthquakes along this plate boundary, including the strongest earthquake ever measured. Most recently, the boundary ruptured in 2010
in central Chile.
to Coquimbo
. The tsunami
killed several hundred people in coastal cities, especially in Coquimbo.
Total damages were estimated to be in the range $5–25 million U.S. (1922 dollars).
s on 3 and 7 November. The main shock lasted between thirty seconds and eight minutes according to various reports.
The length of the plate boundary that ruptured during the earthquake is estimated to be 390 km.
of the earthquake was well inland and the tsunami may have been caused by a submarine slide triggered by the shaking.
At Caldera
the tsunami began about 15 minutes after the earthquake, with a maximum run-up height of 7 m. At Chañaral
the tsunami had three surges, the first about an hour after the earthquake, the maximum run-up height was 9 m. Three surges were also seen at Coquimbo, the last being the most destructive with a maximum run-up of 7 m.
The tsunami was also observed in Callao
, Peru
(2.4 m), California
(0.2 m 13.0 hours delay), Hawaii
(2.1 m 14.5 hours), Samoa
(0.9 m 14.1 hours), Japan
(0.3 m), Taiwan
(0.03 m), New Zealand
(0.1 m), Australia
(0.2 m) and the Philippines
(0.1 m).
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...
8.5 earthquake
Earthquake
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...
that occurred in the Atacama Region
Atacama Region
The Atacama Region is one of Chile's 15 first order administrative divisions. It comprises three provinces, Chañaral, Copiapó and Huasco. It is bordered to the north by Antofagasta, to the south by Coquimbo, to east with Provinces of Catamarca, La Rioja and San Juan of Argentina, and to west with...
of Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
, near the border with Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
on November 11, 1922 at 04:32 UTC. It triggered a destructive tsunami that caused significant damage to the coast of Chile and was observed as far away as Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
.
Tectonic setting
The earthquake took place along the boundary between the NazcaNazca Plate
]The Nazca 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...
and South American
South American Plate
The South American Plate is a continental tectonic plate which includes the continent of South America and also a sizeable region of the Atlantic Ocean seabed extending eastward to the Mid-Atlantic Ridge....
tectonic plates
Tectonic Plates
Tectonic Plates is a 1992 independent Canadian film directed by Peter Mettler. Mettler also wrote the screenplay based on the play by Robert Lepage. The film stars Marie Gignac, Céline Bonnier and Robert Lepage.-Plot summary:...
, at a location where they converge
Convergent boundary
In plate tectonics, a convergent boundary, also known as a destructive plate boundary , is an actively deforming region where two tectonic plates or fragments of lithosphere move toward one another and collide...
at a rate of seventy millimeters a year.
Chile has been at a convergent plate boundary that generates megathrust earthquake
Megathrust earthquake
Megathrust earthquakes occur at subduction zones at destructive plate boundaries , where one tectonic plate is forced under another. Due to the shallow dip of the plate boundary, which causes large sections to get stuck, these earthquakes are among the world's largest, with moment magnitudes ...
s since the Paleozoic
Paleozoic
The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...
(500 million years ago). In historical times the Chilean coast has suffered many megathrust earthquakes along this plate boundary, including the strongest earthquake ever measured. Most recently, the boundary ruptured in 2010
2010 Chile earthquake
The 2010 Chile earthquake occurred off the coast of central Chile on Saturday, 27 February 2010, at 03:34 local time , having a magnitude of 8.8 on the moment magnitude scale, with intense shaking lasting for about three minutes. It ranks as the sixth largest earthquake ever to be recorded by a...
in central Chile.
Damage and deaths
The earthquake caused extensive damage in a zone extending approximately from CopiapoCopiapó
Copiapó is a city in northern Chile, located about 40 miles east of the coastal town of Caldera. Founded on December 8, 1744, it is the capital of Copiapó Province and Atacama Region....
to Coquimbo
Coquimbo
Coquimbo is a port city, commune and capital of the Elqui Province, located on the Pan-American Highway, in the Coquimbo Region of Chile. Coquimbo lies in a valley south of La Serena, with which it forms Greater La Serena with more than 400,000 inhabitants. The commune spans an area around the...
. The tsunami
Tsunami
A tsunami is a series of water waves caused by the displacement of a large volume of a body of water, typically an ocean or a large lake...
killed several hundred people in coastal cities, especially in Coquimbo.
Total damages were estimated to be in the range $5–25 million U.S. (1922 dollars).
Earthquake
The earthquake was preceded by strong foreshockForeshock
A foreshock is an earthquake that occurs before a larger seismic event and is related to it in both time and space. The designation of an earthquake as foreshock, mainshock or aftershock is only possible after the event....
s on 3 and 7 November. The main shock lasted between thirty seconds and eight minutes according to various reports.
The length of the plate boundary that ruptured during the earthquake is estimated to be 390 km.
Tsunami
The epicenterEpicenter
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...
of the earthquake was well inland and the tsunami may have been caused by a submarine slide triggered by the shaking.
At Caldera
Caldera, Chile
Caldera is a port city in the Copiapó Province of the Atacama Region in northern Chile. It has an excellent harbor, protected by breakwaters, being the port city for the productive mining district centering on Copiapó to which it is connected by the first railroad constructed in Chile.-Geography...
the tsunami began about 15 minutes after the earthquake, with a maximum run-up height of 7 m. At Chañaral
Chañaral
Chañaral is a small coastal city and commune in the Atacama Region, Chile and capital of the Chañaral Province. A colourful town largely unknown by tourists, who generally head straight for towns such as San Pedro de Atacama. The town is considered unspoiled, with the benefit of having absolutely...
the tsunami had three surges, the first about an hour after the earthquake, the maximum run-up height was 9 m. Three surges were also seen at Coquimbo, the last being the most destructive with a maximum run-up of 7 m.
The tsunami was also observed in Callao
Callao
Callao is the largest and most important port in Peru. The city is coterminous with the Constitutional Province of Callao, the only province of the Callao Region. Callao is located west of Lima, the country's capital, and is part of the Lima Metropolitan Area, a large metropolis that holds almost...
, Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
(2.4 m), California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
(0.2 m 13.0 hours delay), Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
(2.1 m 14.5 hours), Samoa
Samoa
Samoa , officially the Independent State of Samoa, formerly known as Western Samoa is a country encompassing the western part of the Samoan Islands in the South Pacific Ocean. It became independent from New Zealand in 1962. The two main islands of Samoa are Upolu and one of the biggest islands in...
(0.9 m 14.1 hours), Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
(0.3 m), Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
(0.03 m), New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
(0.1 m), Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
(0.2 m) and the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
(0.1 m).