Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by ERICKSEN, G. E. Articles by SILGADO, E. Search for Related Content GeoRef GeoRef Citation

The Cusco, Peru, Earthquake of May 21, 1950^*

Abstract

On May 21, 1950, an earthquake seriously damaged more than half the buildings of Cusco, Peru. It occurred without warning of foreshocks and was followed by only a few weak aftershocks. The epicentral area, within which buildings were extensively damaged, covered only about 12 square kilometers within the Cusco Basin, and minor damage was limited to a surrounding area of less than 500 square kilometers. The earthquake was felt over a total area of only 15,000 to 16,000 square kilometers and therefore may be considered local in effect. The depth of focus probably was between 8 and 9 kilometers.

The maximum intensity in the epicentral area was estimated to be VII on the Modified Mercalli scale, and the acceleration was less than 300 gals. The extensive damage in the epicentral area is attributed largely to poor construction and the age of buildings. The buildings that were most seriously damaged were colonial churches 250 to 350 years old, old adobe houses, and new houses of combined adobe and rock or brick construction. Many of the buildings that were destroyed in this earthquake had previously been damaged during an earthquake in 1941.

From a summary of the geology of the Cusco Basin it is concluded that the most extensive damage was to buildings resting on thick water-saturated alluvial gravels.

The earthquake was probably of tectonic origin, but there is no positive evidence of active faulting. However, an extensive fissure zone in unconsolidated sediments at the south side of the Cusco Basin may be related to a bedrock fault beneath these sediments.

Footnotes

^* Manuscript received for publication January 2, 1952.

This article has been cited by other articles:

				J. Cabrera and M. Sebrier Surface rupture associated with a 5.3-mb earthquake: The 5 April 1986 Cuzco earthquake and kinematics of the Chincheros-Quoricocha faults of the High Andes, Peru Bulletin of the Seismological Society of America, February 1, 1998; 88(1): 242 - 255. [Abstract] [PDF]