Report on Sabancaya (Peru) — 26 September-2 October 2018
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
26 September-2 October 2018
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2018. Report on Sabancaya (Peru). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 26 September-2 October 2018. Smithsonian Institution and US Geological Survey.
15.787°S, 71.857°W; summit elev. 5960 m
All times are local (unless otherwise noted)
Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 21 per day during 24-30 September. Hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 3.7 km above the crater rim and drifted 50 km E, SE, and SW. The MIROVA system detected six thermal anomalies, and on 29 September the sulfur dioxide gas flux was high at 3,250 tons/day. The report noted that the public should not approach the crater within a 12-km radius.
Geological Summary. 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.