Report on Sabancaya (Peru) — July 1991
Bulletin of the Global Volcanism Network, vol. 16, no. 7 (July 1991)
Managing Editor: Lindsay McClelland.
Sabancaya (Peru) Earthquake swarm damages towns and triggers mudslides; 20 people reported dead
Please cite this report as:
Global Volcanism Program, 1991. Report on Sabancaya (Peru). In: McClelland, L (ed.), Bulletin of the Global Volcanism Network, 16:7. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199107-354006.
15.787°S, 71.857°W; summit elev. 5960 m
All times are local (unless otherwise noted)
A swarm of earthquakes, reported on 23-24 July, triggered mudslides that partly buried four villages. In towns within 20 km N of the volcano, the earthquakes caused many houses to collapse, especially in Maca (15 km N) which was almost completely destroyed. The press reported that 20 people were killed, 80 were injured, and 3,000 were left homeless. More than 20 earthquakes/day were reported felt (MM <=V) 75 km SE (in Arequipa). The largest of the shocks (Ms [4.7]), detected at  on 23 July by the WWSSN, was centered  km [ENE] from the volcano at shallow depth.
Geologic Background. Sabancaya, located in the saddle NE of Ampato and SE of Hualca Hualca volcanoes, is the youngest of these volcanic centers and the only one to have erupted in historical time. The oldest of the three, Nevado Hualca Hualca, is of probable late-Pliocene to early Pleistocene age. The name Sabancaya (meaning "tongue of fire" in the Quechua language) first appeared in records in 1595 CE, suggesting activity prior to that date. Holocene activity has consisted of Plinian eruptions followed by emission of voluminous andesitic and dacitic lava flows, which form an extensive apron around the volcano on all sides but the south. Records of historical eruptions date back to 1750.
Information Contacts: NEIC; EFE network, Madrid, Spain; Agence France-Presse; Reuters; UPI; AP.