Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that an average of 18 explosions per day occurred at Sabancaya during 10-16 December.
Long-period seismic events were recorded, and hybrid earthquakes were infrequent and of low magnitude.
Gas-and-ash plumes rose as high as 2.2 km above the crater rim and drifted 40 km W and SW.
MIROVA detected five thermal anomalies, and on 13 December the sulfur-dioxide gas flux was high at 3,100 tons per day.
The report noted that the public should not approach the crater within a 12-km radius.
Sources: Instituto Geofísico del Perú (IGP),Instituto Geológico Minero y Metalúrgico (INGEMMET)