Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 10-16 April seismicity at Sabancaya increased compared to the previous week, with an average of 37 explosions recorded per day. Ash plumes rose as high as 3 km above the crater rim (13 April) and drifted more than 40 km NW and SE. The Buenos Aires VAAC reported that on 17 April ash plumes rose to an altitude of 7.9 km (26,000 ft) a.s.l. and drifted SE. The next day ash emissions were recorded by the webcam. The Alert Level remained at Orange (the second highest level on a four-color scale).

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), Instituto Geológico Minero y Metalúrgico (INGEMMET), Buenos Aires Volcanic Ash Advisory Center (VAAC)