The 1970 Ancash earthquake (also known as the Great Peruvian earthquake) occurred on 31 May off the coast of

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 ...

in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

at . Combined with a resultant landslide, it is the most catastrophic natural disaster in the

history of Peru The history of Peru spans 10 millennia, extending back through several stages of cultural development along the country's desert coastline and in the Andes mountains. Peru's coast was home to the Norte Chico civilization, the oldest civilization i ...

. Due to the large amounts of snow and ice included in the landslide that caused an estimate of 66,794 to 70,000 casualties, it is also considered to be the world's deadliest

avalanche An avalanche is a rapid flow of snow down a slope, such as a hill or mountain. Avalanches can be set off spontaneously, by such factors as increased precipitation or snowpack weakening, or by external means such as humans, animals, and earth ...

Earthquake

The

undersea earthquake A submarine, undersea, or underwater earthquake is an earthquake that occurs underwater at the bottom of a body of water, especially an ocean. They are the leading cause of tsunamis. The magnitude can be measured scientifically by the use of the ...

struck on a Sunday afternoon and lasted about 45 seconds. The shock affected the

vian regions of

Ancash Ancash ( qu, Anqash; es, Áncash ) is a department and region in northern Peru. It is bordered by the departments of La Libertad on the north, Huánuco and Pasco on the east, Lima on the south, and the Pacific Ocean on the west. Its capital i ...

and La Libertad. 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 ...

was located off the coast of

Casma Casma is a city in the coastal desert of Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = National s ...

and

Chimbote Chimbote ; qu, Chimputi) is the largest city in the Ancash Region of Peru, and the capital of both Santa Province and Chimbote District. The city is located on the coast in Ferrol Bay, 130 km south of Trujillo and north of Lima on the No ...

in the

, where the Nazca Plate 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 The South American Plate is a major tectonic plate which includes the continent of South America as well as a sizable region of the Atlantic Ocean seabed extending eastward to the African Plate, with which it forms the southern part of the Mid-A ...

. It had 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 7.9 and a maximum

Mercalli intensity The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the eff ...

of VIII (''Severe''). The

focal mechanism The focal mechanism of an earthquake describes the deformation in the source region that generates the seismic waves. In the case of a fault-related event it refers to the orientation of the fault plane that slipped and the slip vector and is ...

and hypocentral depth of the earthquake show that the earthquake was a result of

normal fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

ing within the subducting slab.

Damage

The earthquake affected an area of about 83,000 km², an area larger than

Belgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to th ...

and the

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

combined, in the north-central coast and the Sierra (highlands) of the

Ancash Region Ancash ( qu, Anqash; es, Áncash ) is a department and region in northern Peru. It is bordered by the departments of La Libertad on the north, Huánuco and Pasco on the east, Lima on the south, and the Pacific Ocean on the west. Its capital i ...

and southern

La Libertad Region La Libertad (; in English: ''The Liberty'') is a region in northwestern Peru. Formerly it was known as the Department of La Libertad ('). It is bordered by the Lambayeque, Cajamarca and Amazonas regions on the north, the San Martín Region on t ...

. Reports of damage and casualties came from Tumbes to Pisco and

Iquitos Iquitos (; ) is the capital city of Peru's Maynas Province and Loreto Region. It is the largest metropolis in the Peruvian Amazon, east of the Andes, as well as the ninth-most populous city of Peru. Iquitos is the largest city in the world th ...

in the east. Damage and panic scenes were reported in some parts of

Ecuador Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ''Eku ...

. Tremors were also felt in western and central

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

. It was a system-wide disaster, affecting such a widespread area that the regional infrastructure of communications, commerce, and transportation was destroyed. Economic losses surpassed half a billion US dollars. Cities, towns, villages—and homes, industries, public buildings, schools, electrical generation and distribution systems, water, sanitary and communications facilities—were seriously damaged or were destroyed. Areas hard hit were the coastal towns and cities of

(the largest city in Ancash),

, Supe and

Huarmey ''For the Province of the Ancash Region in Peru, see Huarmey Province'' Huarmey is a coastal town in the Ancash Region, Peru. It is one of the five districts and also the capital of the Province of Huarmey. It is located crossing the Pan-America ...

; but the

Andean The Andes, Andes Mountains or Andean Mountains (; ) are the List of mountain ranges#Mountain ranges by length, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range i ...

valley known as the

Callejón de Huaylas The Santa Valley (Quechua language, Quechua ''Sancta'') is an inter-andean valley in the Ancash Region in the north-central highlands of Peru. Due to its location between two mountain ranges, it is known as Callejón de Huaylas, the Alley of Huayla ...

suffered the most intense and sweeping damage, with the regional capital,

Huaraz Huaraz () (from Quechuan languages, Quechua: ''Waraq'' or ''Waras'', "''dawn''"), founded as San Sebastián de Huaraz, is a city in Peru. It is the capital of the Ancash Region (State of Ancash) and the seat of government of Huaraz Province. The ...

, and

Caraz Caraz is a town in the Caraz District in the southeastern part of Huaylas Province of the Ancash Region in Peru. Political Creation Recent investigations suggest that its political creation happened on 12 February 1821 when General San Martín, ...

and Aija being partially destroyed. Trujillo, the country's third-largest city, and

suffered minor damage. In Chimbote, Carhuaz and Recuay, about 80% to 90% of buildings were destroyed, affecting about three million people. The

Pan-American highway The Pan-American Highway (french: (Auto)route panaméricaine/transaméricaine; pt, Rodovia/Auto-estrada Pan-americana; es, Autopista/Carretera/Ruta Panamericana) is a network of roads stretching across the Americas and measuring about in to ...

was also damaged, which made the arrival of

humanitarian aid Humanitarian aid is material and logistic assistance to people who need help. It is usually short-term help until the long-term help by the government and other institutions replaces it. Among the people in need are the homeless, refugees, and ...

difficult. The Cañón del Pato

hydroelectricity Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other Renewabl ...

generator was damaged by the

Santa River The Santa River ( es, Río Santa) is a river in the South American Andes mountain range in the Ancash Region of northwest central Peru. River Course Lake Conococha, at an altitude of 4,050 m above sea level and at , is considered the headwate ...

and the

railway Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...

connecting Chimbote with the Santa Valley was left unusable on 60% of its route. The Peruvian government has forbidden excavation in the area where the town of Yungay is buried, declaring it a national cemetery. The children who survived in the local stadium were resettled around the world. In 2000, the tragedy inspired the government to declare 31 May as ''Natural Disaster Education and Reflection Day''. Every 31 May, many schools of Peru practise an earthquake drill to commemorate this disaster.

Landslide

The northern wall of Mount

Huascarán Huascarán () (Quechua: Waskaran), Nevado Huascarán or Mataraju is a mountain in the Peruvian province of Yungay (Ancash Department), situated in the Cordillera Blanca range of the western Andes. The southern summit of Huascarán (Huascarán ...

was destabilized, causing a rock, ice and snow

and burying the towns of Yungay and

Ranrahirca Ranrahirca was a village in Peru, alongside the river Santa, near Huascarán, the highest mountain in Peru. It was hit by massive avalanches of snow, rocks and mud, originating on the slopes of Huascarán and triggered by earthquakes on 10 Januar ...

. The avalanche started as a sliding mass of

glacial A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betw ...

ice and rock about wide and 1.6 km (1 mile) long. It advanced about to the village of Yungay at an average speed of 280 to 335 km per hour. The fast-moving mass picked up glacial

deposits A deposit account is a bank account maintained by a financial institution in which a customer can deposit and withdraw money. Deposit accounts can be savings accounts, Transaction account#Current accounts, current accounts or any of several othe ...

and by the time it reached Yungay, it is estimated to have consisted of about 80 million m³ of water, mud, rocks and snow.

References

Sources *

External links

IRIS SeismoArchive for 1970 Peru earthquake
–

IRIS Consortium IRIS (Incorporated Research Institutions for Seismology) is a university research consortium dedicated to exploring the Earth's interior through the collection and distribution of seismographic data. IRIS programs contribute to scholarly research, ...

Yungay 1970–2009: remembering the tragedy of The Earthquake
– Peruvian Times
"In pictures: Peru's most catastrophic natural disaster"
BBC News website (accessed and dated 31 May 2020) *
Documentary Footage by Texan Relief Workers in Peru, Ancash Earthquake of 1970
on

Texas Archive of the Moving Image The Texas Archive of the Moving Image (TAMI) is an independent 501(c)(3) organization founded in 2002 by film archivist and University of Texas at Austin professor Caroline Frick, PhD. TAMI's mission is to preserve, study, and exhibit Texas film h ...

{{Earthquakes in Peru Ancash earthquake 1970 Earthquakes in Peru Ancash earthquake

1970 in Peru 1970 tsunamis Ancash earthquake May 1970 events in South America 1970 disasters in South America

Earthquake

Damage

Landslide

See also

References

External links