1730 Valparaiso earthquake
Encyclopedia
The 1730 Valparaíso earthquake occurred at 08:45 UTC on July 8. It had an estimated magnitude
of 8.7 and triggered a major tsunami
with an estimated magnitude of Mt=8.75, that inundated the lower parts of Valparaíso
. The earthquake caused severe damage from La Serena to Chillan
, while the tsunami affected more than 1000 km (621.37 mi) of Chile
's coastline.
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.
, Coquimbo
, Illapel
, Petorca
and Tiltil were all affected. The parish church in La Serena was destroyed.
Only a few deaths were recorded due to the earthquake, reportedly because a strong foreshock
had caused people to leave their homes. The same is also true for the following tsunami with the inhabitants running to higher ground after seeing the water recede, so that only a few were killed.
, there was a strong earthquake, followed by several smaller tremors. The main shock occurred at 4:45 local time.
A 350–550 km (341.76 mi) long rupture has been estimated for this event, from the extent of severe damage.
of 16 m. It was also observed at Callao
, Peru
and in Honshu
, Japan
where fields were flooded in Rikuzen and the Oshika Peninsula
.
Surface wave magnitude
The surface wave magnitude scale is one of the magnitude scales used in seismology to describe the size of an earthquake. It is based on measurements in Rayleigh surface waves that travel primarily along the uppermost layers of the earth...
of 8.7 and triggered a major 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...
with an estimated magnitude of Mt=8.75, that inundated the lower parts of Valparaíso
Valparaíso
Valparaíso is a city and commune of Chile, center of its third largest conurbation and one of the country's most important seaports and an increasing cultural center in the Southwest Pacific hemisphere. The city is the capital of the Valparaíso Province and the Valparaíso Region...
. The earthquake caused severe damage from La Serena to Chillan
Chillán
Chillán is a city in the Biobío Region of Chile located about south of the country's capital, Santiago, near the geographical center of the country. It is the capital of Ñuble Province and, with a population of approximately 170,000 people , the most populated urban center of this province...
, while the tsunami affected more than 1000 km (621.37 mi) 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...
's coastline.
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
The earthquake caused severe damage over a wide area, ValparaísoValparaíso
Valparaíso is a city and commune of Chile, center of its third largest conurbation and one of the country's most important seaports and an increasing cultural center in the Southwest Pacific hemisphere. The city is the capital of the Valparaíso Province and the Valparaíso Region...
, 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...
, Illapel
Illapel
Illapel is a Chilean city, which is the capital of the Choapa Province, Coquimbo Region. It lies along the Illapel River and marks the country's narrowest point along a parallel .It's located to the east of Los Vilos.-Administration:...
, Petorca
Petorca Province
Petorca Province is one of eight provinces of the central Chilean region of Valparaíso . Its capital is the city of La Ligua.-Administration:...
and Tiltil were all affected. The parish church in La Serena was destroyed.
Only a few deaths were recorded due to the earthquake, reportedly because a strong foreshock
Foreshock
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....
had caused people to leave their homes. The same is also true for the following tsunami with the inhabitants running to higher ground after seeing the water recede, so that only a few were killed.
Earthquake
At about 01:00 local time in SantiagoSantiago, Chile
Santiago , also known as Santiago de Chile, is the capital and largest city of Chile, and the center of its largest conurbation . It is located in the country's central valley, at an elevation of above mean sea level...
, there was a strong earthquake, followed by several smaller tremors. The main shock occurred at 4:45 local time.
A 350–550 km (341.76 mi) long rupture has been estimated for this event, from the extent of severe damage.
Tsunami
The tsunami occurred immediately after the mainshock, with a maximum run-up height recorded at ConcepciónConcepción, 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...
of 16 m. It was also observed at 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....
and in Honshu
Honshu
is the largest island of Japan. The nation's main island, it is south of Hokkaido across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyushu across the Kanmon Strait...
, 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...
where fields were flooded in Rikuzen and the Oshika Peninsula
Oshika Peninsula
The Oshika Peninsula is a peninsula which projects southeast into the Pacific Ocean from the coast of Miyagi Prefecture in northeast Honshu, the main island of Japan....
.