The 1922 Vallenar earthquake occurred with a

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 ...

of 8.5–8.6 and a tsunami magnitude of 8.7 in the Atacama Region of

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

, near the border with

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

on 11 November 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, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

Tectonic setting

The earthquake took place along the boundary between the

Nazca Nazca (; sometimes spelled Nasca; qu, Naska) is a city and system of valleys on the southern coast of Peru. It is also the name of the largest existing town in the Nazca Province. The name is derived from the Nazca culture, which flourished in ...

and

South American South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

tectonic plates Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large te ...

, at a location where they

converge Converge may refer to: * Converge (band), American hardcore punk band * Converge (Baptist denomination), American national evangelical Baptist body * Limit (mathematics) * Converge ICT, internet service provider in the Philippines *CONVERGE CFD s ...

at a rate of seventy millimeters a year. Chile has been at a convergent plate boundary that generates

megathrust earthquake Megathrust earthquakes occur at convergent plate boundaries, where one tectonic plate is forced underneath another. The earthquakes are caused by slip along the thrust fault that forms the contact between the two plates. These interplate earthqua ...

s since the

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ' ...

(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.

Damage and deaths

The earthquake caused extensive damage in a zone extending approximately from

Copiapó Copiapó () is a city and commune in northern Chile, located about 65 kilometers east of the coastal town of Caldera. Founded on December 8, 1744, it is the capital of Copiapó Province and Atacama Region. Copiapó lies about 800 km north ...

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 is situated in a valley south of La Serena, with which it forms Greater La Serena with more than ...

. Newspapers estimated more than 1,000 dead as a result of the quake, at least 500 of them in Vallenar. The

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 explo ...

killed several hundred people in coastal cities, especially in Coquimbo. Total damage was estimated to be in the range of $5–25 million U.S. (1922 dollars).USGS, ''Historic Earthquakes.Chile-Argentina Border. 1922 November 11 04:32 UTC. Magnitude 8.5''
/ref>Dunbar, Paula K., Lockridge, Patricia A., and Whiteside, Lowell S., 1992, Catalog of significant earthquakes 2150 B.C. – 1991 A.D.: U. S. Dept. of Commerce, National Oceanic and Atmospheric Administration.

Characteristics

Earthquake

Casas colapsadas por terremoto de Vallenar de 1922

The earthquake was preceded by strong

foreshock A foreshock is an earthquake that occurs before a larger seismic event (the mainshock) 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 full sequ ...

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 (242 mi).

Tsunami

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 ...

of the earthquake was well inland and the tsunami may have been caused by a submarine slide triggered by the shaking. At

Caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...

the tsunami began about 15 minutes after the earthquake, with a maximum run-up height of 7 m (23 ft). At

Chañaral Chañaral is a small coastal city and commune in the Atacama Region, Chile and capital of the Chañaral Province. It is largely unknown by tourists, who generally head straight for towns such as San Pedro de Atacama. The town has no high rise bu ...

the tsunami had three surges, the first about an hour after the earthquake, the maximum run-up height was 9 m (30 ft). Three surges were also seen at Coquimbo, the last being the most destructive with a maximum run-up of 7 m (23 ft). The tsunami was also observed in

Callao Callao () is a Peruvian seaside city and Regions of Peru, region on the Pacific Ocean in the Lima metropolitan area. Callao is Peru's chief seaport and home to its main airport, Jorge Chávez International Airport. Callao municipality consists o ...

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

(2.4 m, 7.9 ft),

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

(0.2 m, 8 in 13.0 hours delay),

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

(2.1 m, 6.9 ft 14.5 hours),

Samoa Samoa, officially the Independent State of Samoa; sm, Sāmoa, and until 1997 known as Western Samoa, is a Polynesian island country consisting of two main islands (Savai'i and Upolu); two smaller, inhabited islands (Manono Island, Manono an ...

(0.9 m, 3 ft 14.1 hours),

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

(0.3 m, 1 ft),

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...

(0.03 m, 1 in),

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

(0.1 m, 3.9 in),

(0.2 m, 7.9 in) and the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

(0.1 m, 3.9 in).

References

External links

* * {{Earthquakes in Chile Megathrust earthquakes in Chile

Vallenar Vallenar is a city and commune in Atacama Region, Chile. It is the capital of the Huasco Province and is located in the valley of the Huasco River. Vallenar has 52,000 inhabitants. Its main activities are farming and mining. It was founded as San ...

Vallenar Earthquake, 1922 1922 tsunamis Tsunamis in New Zealand 1922 disasters in South America 1922 disasters in Oceania