The 1996 Chimbote earthquake occurred on February 21, 1996 at 07:51 local time (12:51 UTC) about 130 km off the coast of northern 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....

, near the Peru-Chile Trench

Peru-Chile Trench

The Peru-Chile Trench, also known as the Atacama Trench, is an oceanic trench in the eastern Pacific Ocean, about 160 kilometres off the coast of Peru and Chile...

. It was an earthquake of magnitude M_w 7.4.

Geology

The mechanism inferred from data is a low-angle thrust of 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...

, which is subducting beneath 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....

. This earthquake occurred in an area where the Peru-Chile subduction zone is relatively quiet.

Tsunami

This earthquake was special in that it generated a disproportionally large tsunami. Earthquakes with slow rupture velocities are the most efficient tsunami generators, and the rupture velocity of this earthquake was classified as moderately slow (Newman and Okal, 1996). The tsunami affected the Peruvian coastal area from Pacasmayo

Pacasmayo Province

The Pacasmayo Province is one of twelve provinces of the La Libertad Region in Peru; also Pacasmayo is the name of one of its districts. The capital of this province is the city of San Pedro de Lloc.-Political division:...

, La Libertad

La Libertad Region

La Libertad is a region in northwestern Peru. Formerly it was known as the 'Department of La Libertad" , a political division that generally corresponds to a state in the United States of America...

 to 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...

. The straight line distance between the two areas are about 590 km. The greatest runup value of the tsunami was 5.14 m, recorded at the port of Chimbote, located on the north side of Chimbote Bay. 12 people were killed by the tsunami, all in remote areas, likely due to lack of information. In more populated areas, such as Chimbote

Chimbote

Chimbote 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 Chimbote Bay, south of Trujillo and north of Lima on the North Pan-American highway. It is the start of a chain of important cities like...

, people were aware of the approaching tsunami and were able to evacuate the coast in time. A 60 cm tsunami was recorded in Easter Island

Easter Island

Easter Island is a Polynesian island in the southeastern Pacific Ocean, at the southeasternmost point of the Polynesian triangle. A special territory of Chile that was annexed in 1888, Easter Island is famous for its 887 extant monumental statues, called moai, created by the early Rapanui people...

 and 25 cm in Hilo.

Aftershocks

The aftershock pattern of this earthquake ranged from 120 to 180 km off the coast and seemed to parallel the Peru-Chile Trench and the Peruvian coastline. Of the mechanisms of two of the larger aftershocks, one was a shallow thrust, and the other one was normal faulting.