Based on webcam and satellite views, and seismic data, the Buenos Aires VAAC reported that sporadic gas-and-ash puffs rose from Sabancaya during 25-31 January. Weather clouds sometimes prevented visual observations. A field team from IGP's Observatorio Vulcanológico del Sur (OVS) visited Sabancaya on 26 January and observed ash plumes from explosions rising about 2 km above the crater rim.

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)