During April 1819, the area around

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 ...

in northern

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 ...

was struck by a sequence of earthquakes over a period of several days. The largest of these earthquakes occurred on 11 April at about 15:00 local time, with an estimated magnitude of 8.5. The other two events, on 3 April between 08:00 and 09:00 local time and on 4 April at 16:00 local time, are interpreted as

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 to the mainshock on 11 April. The mainshock triggered 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 explo ...

that affected 800 km of coastline and was also recorded at

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 ...

. The city of Copiapó was devastated.

Tectonic setting

Northern Chile lies above the destructive plate boundary where the

Nazca 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 Na ...

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 ...

beneath the South American Plate along the line of

Peru–Chile Trench The Peru–Chile Trench, also known as the Atacama Trench, is an oceanic trench in the eastern Pacific Ocean, about off the coast of Peru and Chile. It reaches a maximum depth of below sea level in Richards Deep () and is approximately long; ...

at about 8 cm per year. This part of the boundary is associated with many large

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, including those in 1420 and

1922 Events January * January 7 – Dáil Éireann (Irish Republic), Dáil Éireann, the parliament of the Irish Republic, ratifies the Anglo-Irish Treaty by 64–57 votes. * January 10 – Arthur Griffith is elected President of Dáil Éirean ...

Earthquake sequence

The magnitudes of the two foreshocks is not known. The magnitude of the mainshock has been estimated to be 8.5. The earthquake sequence is though to have ruptured the same part of the plate boundary as that ruptured by the 1922 Vallenar earthquake.

Tsunami

The tsunami triggered by the 11 April mainshock affected at least 800 km of the Chilean coastline, with a maximum run-up height of 4 m and a maximum inundation of 600 m. Places affected included

Huasco Huasco () is a Chilean city and commune, in the Huasco Province, Atacama Region. The port city of Huasco is located 50 km west of Vallenar and close to the town of ''Huasco Bajo'', which lies on the southern bank of the Huasco River and o ...

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 ...

, and Concepción. Caldera suffered significant damage and at Concepción the

schooner A schooner () is a type of sailing vessel defined by its rig: fore-and-aft rigged on all of two or more masts and, in the case of a two-masted schooner, the foremast generally being shorter than the mainmast. A common variant, the topsail schoon ...

''La Fortuna'' broke free from its moorings. The tsunami was also recorded in the

Hawaiian Islands The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Kur ...

Honolulu Honolulu (; ) is the capital and largest city of the U.S. state of Hawaii, which is in the Pacific Ocean. It is an unincorporated county seat of the consolidated City and County of Honolulu, situated along the southeast coast of the island ...

Hilo Hilo () is a census-designated place (CDP) and the largest settlement in Hawaii County, Hawaii, Hawaii County, Hawaii, United States, which encompasses the Hawaii (island), Island of Hawaii. The population was 44,186 according to the 2020 United ...

Kahului Kahului () is a census-designated place (CDP) in Maui County in the U.S. state of Hawaii. It hosts the county's main airport (Kahului Airport), deep-draft harbor, light industrial areas, and commercial shopping centers. The population was 26,337 ...

and

Molokai Molokai , or Molokai (), is the fifth most populated of the eight major islands that make up the Hawaiian Islands, Hawaiian Islands archipelago in the middle of the Pacific Ocean. It is 38 by 10 miles (61 by 16 km) at its greatest length an ...

. It may also have been observed at

Mangareva Mangareva is the central and largest island of the Gambier Islands in French Polynesia. It is surrounded by smaller islands: Taravai in the southwest, Aukena and Akamaru in the southeast, and islands in the north. Mangareva has a permanent pop ...

French Polynesia )Territorial motto: ( en, "Great Tahiti of the Golden Haze") , anthem = , song_type = Regional anthem , song = " Ia Ora 'O Tahiti Nui" , image_map = French Polynesia on the globe (French Polynesia centered).svg , map_alt = Location of Frenc ...

Impact

The earthquake sequence caused major damage in both Copiapó and

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 ...

. The 3 April foreshock led to widespread damage in Copiapó. The 4 April foreshock caused the collapse of several buildings in the city including a church, killing "many people". The effects of the mainshock on 11 April and its associated tsunami, combined with those of the foreshocks was the complete destruction of Copiapó and Caldera.

References

{{Earthquakes in Chile Earthquakes in Chile 1819 earthquakes 1819 in Chile

Tectonic setting

Earthquake sequence

Tsunami

Impact

See also

References