Report on Sabancaya (Peru) — 9 November-15 November 2016
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 9 November-15 November 2016
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2016. Report on Sabancaya (Peru). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 9 November-15 November 2016. Smithsonian Institution and US Geological Survey.
15.787°S, 71.857°W; summit elev. 5960 m
All times are local (unless otherwise noted)
A Technical and Scientific Committee for volcanic risk management of the Arequipa region is comprised of five groups including IGP's Observatorio Vulcanológico del Sur (OVS) and INGEMMET's Observatorio Vulcanológico (OVI) and have been monitoring Sabancaya since 2013. The committee reported that new ash-bearing explosions began on 6 November. The explosions, detected at 2126, 2127, and 2149, produced ash plumes that rose 1.5 km above the crater rim and drifted E.
The frequency of hybrid earthquakes increased noticeably in early October and in the hours prior to the 6 November explosions. Volcanic gas emissions had also increased significantly, with values as high as 7,173 tons/day on 23 October. The MIROVA system had detected a thermal anomaly at the volcano on 2 November.
During 6-13 November ash-and-gas emissions from explosions and from periods in between explosions rose as high as 3 km above the crater. An event at 1320 on 8 November generated a significant ash plume that rose 2.4 km above the crater rim with ash dispersing within a 5-km radius. During 9-10 November ash plumes rose as high as 2 km and drifted 30-35 km SE, E, and NE, producing ashfall in the villages of Valle del Colca to the NE. On 11 November an explosion generated an ash plume that rose 3 km and drifted 40 km E and NE. An ash plume from an explosion the next day rose 2 km and drifted 30 km NE.
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.