IGP reported that during 21-27 October seismic activity at Sababcaya was low, and sporadic white and blue plumes rose as high as 1.2 km. Although a pilot reported an ash plume drifting E on 23 October, the Buenos Aires VAAC reported that ash was not detected in satellite images. The webcam showed gas-and-steam emissions, likely with diffuse ash, dissipating near the summit. On 25 October a pilot reported ash drifting E, but again satellite images did not detected ash.

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 observed eruptions date back to 1750 CE.

Sources: Instituto Geofísico del Perú (IGP), Buenos Aires Volcanic Ash Advisory Center (VAAC)