Historic Earthquakes

Off the coast of central Peru
1942 August 24 22:50 UTC
Magnitude 8.2

1942 24 August, at 17:51 hours (local time). Earthquake in the boundary area of the departments of Ica and Arequipa, situated between the 14° and 16°S parallels. Intensity IX MM, felt in an area of some 18,000 km2, where great destruction occurred. Thirty people were killed by the collapse of dwelling houses and 25 were injured for various reasons. It was felt with an intensity of III-IV on the same scale in an elliptical area of 408,000 km2 which took in the city of Huaraz on the north, Cerro de Pasco and Oxapampa on the NE, Cuzco on the east, and Moquegua on the south.

The effects on structures were noteworthy in the epicentral area. It is estimated that 30% of the buildings in the city of Nazca suffered total ruin. The neighboring towns of Acarí and Jacquí were reduced to rubble. The damage extended to the towns of Quicacha and Atiquipa, and was pronounced at Palpa. In the city of Caravelí only buildings of recent construction withstood the shock. The heavy cupola of the Church of the Lord of Luren, in Ica, collapsed, various slight damage was reported in the houses of that city, as in those of Pisco and Chinchas. The Cordilleran towns of Coracora, Huancapi, and others suffered some damage. In the port of Chala the shaking reached such violence that several people were thrown to the ground when they lost their footing; a witness tells: "The houses rocked like a boat tossed by a storm." The Hotel de Turistas in this place suffered crackings of its walls. Father to the SE the tower of the Cathedral in Arequipa leaned somewhat after the strong shaking.

Among the various effects of this shock were:
a) One meter uplift of a breakwater which served as wharf in the bay of San Juan, evidence of a local emergence of the coast, was claimed to have been observed after the earthquake, according to Broggi (1946).
b) Slides in the hills, on stretches of the access road to the interior, particularly at the altitude of Puquio and other places on the west slope, and also NW of the village of Cangallo on the Atlantic slope.
c) Formation of cracks of several inches extent in the rocky hills of Calpa, jurisdiction of Caravelí.
d) In the harbor of Lomas the sea retreated more than 200 meters, immediately returning to inundate the town, destroying wharves, customs storage houses, and causing injuries.

The seismic movement was strongly felt in the towns of Camaná, Chuquibamba, Aplao, and Mollendo in the department of Arequipa, while in Moquegua, Huancayo, Cerro de Pasco, Ayacucho, Huancavelica, Cuzco, Cajatambo, Huaraz, and Lima it decreased in intensity. According to the majority of the people, the shocked lasted more than a minute. Instrumental data: Approximate geographic location 15°S, 76°W, magnitude 8.2, origin time 22:50:27 GMT.

Abridged from Historia de los sismos mas notables ocurridos en el Perú (1513-1970): Geofísica Panamericana, v. 2, no. 1, January 1973, Enrique Silgado F.