1835 Concepción earthquake
Encyclopedia
The 1835 Concepción earthquake occurred near the neighboring cities of Concepción
and Talcahuano
in Chile
on February 20 at 15:30 local time (11:30 UTC
) and has an estimated magnitude of 8.2 Mfa or 8.1 Ml. The earthquake triggered a tsunami
which caused the destruction of Talcahuano. A total of at least 50 people died from the effects of the earthquake and the tsunami. The earthquake caused damage from San Fernando
in the north to Osorno
in the south. It was felt over a still wider area from Copiapó
in the north to the island of Chiloe
in the south and as far west as the Juan Fernández Islands
.
between the Nazca Plate
and the South American Plate
, with a convergence rate of 66 mm/yr. This boundary has been the site of many historical megathrust earthquakes, including the largest earthquake ever recorded. The rupture area of the 1835 earthquake was noted as a prominent seismic gap
, leading to a forecast of a large earthquake (Mw 8.0–8.5) within a few decades. The recent 2010 Chile earthquake
appears to have ruptured this part of the plate interface.
.
was visiting the area while on his second voyage of the HMS Beagle and recorded his observations of the earthquake in Valdivia
and its effects and the subsequent tsunami in Concepción and Talcahuano. He remarked:
Concepción, Chile
Concepción is a city in Chile, capital of Concepción Province and of the Biobío Region or Region VIII. Greater Concepción is the second-largest conurbation in the country, with 889,725 inhabitants...
and Talcahuano
Talcahuano
Talcahuano is a port city and commune in the Biobío Region of Chile. It is part of the Greater Concepción conurbation. Talcahuano is located in the south of the Central Zone of Chile.-Geography:...
in 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...
on February 20 at 15:30 local time (11:30 UTC
Coordinated Universal Time
Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose...
) and has an estimated magnitude of 8.2 Mfa or 8.1 Ml. The earthquake triggered a 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...
which caused the destruction of Talcahuano. A total of at least 50 people died from the effects of the earthquake and the tsunami. The earthquake caused damage from San Fernando
San Fernando, Chile
San Fernando is the capital of the province of Colchagua, in central Chile, and the second most populated urban center of the O'Higgins Region. Located close to the Tinguiririca River in a fertile valley, San Fernando sits 1,112 feet above sea level...
in the north to Osorno
Osorno, Chile
Osorno is a city and commune in southern Chile and capital of Osorno Province in the Los Lagos Region. It had a population of 145,475, as of the 2002 census...
in the south. It was felt over a still wider area from Copiapó
Copiapó
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....
in the north to the island of Chiloe
Chiloé Archipelago
Chiloé Archipelago consists of several islands lying off the coast of Chile. It is separated from mainland Chile by Chacao Channel in the north, the Sea of Chiloé in the east and Gulf of Corcovado to the southeast. All of the archipelago except Desertores Islands, which are part of Palena...
in the south and as far west as the Juan Fernández Islands
Juan Fernández Islands
The Juan Fernández Islands are a sparsely inhabited island group reliant on tourism and fishing in the South Pacific Ocean, situated about off the coast of Chile, and is composed of three main volcanic islands; Robinson Crusoe Island, Alejandro Selkirk Island and Santa Clara Island, the first...
.
Tectonic setting
Chile lies above the convergent boundaryConvergent 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...
between the Nazca Plate
Nazca 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 the South American Plate
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....
, with a convergence rate of 66 mm/yr. This boundary has been the site of many historical megathrust earthquakes, including the largest earthquake ever recorded. The rupture area of the 1835 earthquake was noted as a prominent seismic gap
Seismic gap
A seismic gap is a segment of an active fault that has not slipped in an unusually long time when compared with other segments along the same structure. Seismic gap hypothesis/theory states that, over long periods of time, the displacement on any segment must be equal to that experienced by all...
, leading to a forecast of a large earthquake (Mw 8.0–8.5) within a few decades. The recent 2010 Chile earthquake
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...
appears to have ruptured this part of the plate interface.
Damage
Concepción was devastated, with most buildings being destroyed. A later survey found that 33% of kiln-dried brick buildings, 71% of mud-brick buildings and 95% of stone-built constructions were destroyed with all the rest being damaged. Despite this degree of damage only 50 people were reported dead. The low level of fatalities was attributed to the gradual increase in the intensity of shaking and that the earthquake occurred during the middle of the day, giving most of the inhabitants time to get clear. The destruction at Talcahuano was greater still due to the effects of the tsunami, which left only the lower parts of some buildings standing. A schooner was swept about 200 m inland, into the middle of the ruined town. There were few deaths, as the inhabitants had time to run up the hills behind the town.Earthquake
The shaking lasted for two minutes, with gradually increasing intensity. At least 300 aftershocks were noted during the next 12 days. The land was instantly uplifted along parts of the coast, as much as 3 m in places, although this was followed by subsidence in the following days.Tsunami
There were three separate waves reported at Talcahuano, the first of which had a run-up of 23 feet (7 m). The maximum run-up of 24 m was recorded at CoelemuCoelemu
Coelemu is a Chilean commune and city in Ñuble Province, Biobío Region. According to the 2002 census, the commune population was 16,082 and has an area of .-Demographics:...
.
Remarks
Charles DarwinCharles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...
was visiting the area while on his second voyage of the HMS Beagle and recorded his observations of the earthquake in Valdivia
Valdivia
-Geography:*Chile** Valdivia, Chile, a city and municipality in the Province of Valdivia** Valdivia River, a river which begins in the city of Valdivia** Valdivia Province, the Province of Valdivia...
and its effects and the subsequent tsunami in Concepción and Talcahuano. He remarked: