Report on Sabancaya (Peru) — 23 September-29 September 2020
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 23 September-29 September 2020
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2020. Report on Sabancaya (Peru). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 23 September-29 September 2020. Smithsonian Institution and US Geological Survey.
15.787°S, 71.857°W; summit elev. 5960 m
All times are local (unless otherwise noted)
Instituto Geofísico del Perú (IGP) reported a daily average of 36 explosions at Sabancaya during 21-27 September. Gas-and-ash plumes rose as high as 2.5 km above the summit and drifted NE, E, SE, SW, and NW. Eleven thermal anomalies over the crater were identified in satellite data. Minor inflation was detected in areas N of Hualca Hualca (4 km N) and on the SE flank. Ashfall was reported in Lluta (30 km SW) and Huanca (75 km SSE) on 24 September. The Alert Level remained at Orange (the second highest level on a four-color scale) and the public were warned to stay outside of a 12-km radius.
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.