Each day during 22-28 November CENAPRED reported 129-324 steam and gas emissions from Popocatépetl that sometimes contained ash. Volcano-tectonic events were detected during 22-24 November, and explosions occurred on 22 and 24 November (4 and 7 events, respectively). At 0945 on 25 November an explosion generated a plume that rose 5 km above the crater rim and drifted SE and NE. Seismicity decreased after the event. Ashfall was reported in areas downwind including in the municipalities of Atlixco, Tochimilco, and San Pedro Benito Juárez. During 28-29 November there were 48 detected emissions. Beginning at 0559 emissions of water vapor, gas, and ash became constant, rising as high as 1.5 km above the crater rim and drifting NE. Incandescent fragments were ejected 300-800 m form the crater, mainly onto the NE flank. Ash fell in Atlixco, Chiautzingo, Domingo Arenas, Huejotzingo, Juan C. Bonilla, San Andrés Calpan, and San Martín Texmelucan (Puebla state), and in San Miguel (Tlaxcala state). The phase of continuous emissions and ejected material ended at 1630 on 30 November. The Alert Level remained at Yellow, Phase Two.

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.

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)