CENAPRED reported that there were 94-206 steam-and-gas emissions, sometimes containing ash, rising from Popocatépetl each day during 17-24 January. The plumes drifted N, NE, and N. Minor ashfall was reported in the municipalities of Domingo Arenas, San Nicolas de los Ranchos, Santiago Xalizintla, in the town of San Mateo Ozolco in Calpan, state of Puebla and in the municipalities of Tlaxcala and Papalotla, state of Tlaxcala on 17 January. On 21 January an ash plume rose as high as 3 km and drifted NNE and one minor explosion was detected. Four explosions were recorded during 21-22 January and six were recorded during 23-24 January. The Alert Level remained at Yellow, Phase Two (the middle level on a three-color scale).

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)