CENAPRED reported that each day during 16-23 November there were 9-29 steam-and-gas emissions from Popocatépetl that drifted NW, NE, and E. At 1714 on 19 November an explosion generated an ash plume that rose 2 km above the crater rim and drifted NE. A minor explosion at 0230 on 21 November generated an ash plume that rose 600 m and drifted NW, and at 0136 the next morning another small explosion produced an ash plume that rose 800 m and drifted NE. The Alert Level remained at Yellow, Phase Two (the middle level on a three-color scale).

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Geological Summary. Volcán Popocatépetl, whose name is the Aztec word for smoking mountain, rises 70 km SE of Mexico City to form North America's 2nd-highest volcano. The glacier-clad stratovolcano contains a steep-walled, 400 x 600 m wide crater. The generally symmetrical volcano is modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier volcano. At least three previous major cones were destroyed by gravitational failure during the Pleistocene, producing massive debris-avalanche deposits covering broad areas to the south. The modern volcano was constructed south of the late-Pleistocene to Holocene El Fraile cone. Three major Plinian eruptions, the most recent of which took place about 800 CE, have occurred since the mid-Holocene, accompanied by pyroclastic flows and voluminous lahars that swept basins below the volcano. Frequent historical eruptions, first recorded in Aztec codices, have occurred since Pre-Columbian time.