Report on Sabancaya (Peru) — 25 October-31 October 2017
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
25 October-31 October 2017
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2017. Report on Sabancaya (Peru). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 25 October-31 October 2017. 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 explosive activity at Sabancaya slightly decreased compared to the previous week; there was an average of 43 explosions recorded per day during 23-29 October. Seismicity was dominated by long-period events, with a relatively steady rate of signals indicating emissions and an increasing number of hybrid events. Gas-and-ash plumes rose 3.9 km above the crater rim and drifted 30 km NW, NE, E, and SE. The MIROVA system detected eight thermal anomalies. The sulfur dioxide flux was high, at 2,635 tons per day on 29 October. The report noted that the public should not to 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.