CENAPRED reported that there were 102-215 steam-and-gas emissions, often containing ash, rising from Popocatépetl each day during 14-21 February; minor explosions also occurred almost daily. Minor explosions were recorded at 1334, 1456, and 1822 on 14 February and at 0253 on 15 February based on data from the seismic network. On 17 February minor explosions occurred at 0210, 1827, 2210, 2252, and 2325. Additional minor explosions were recorded at 0235, 0252, and 0614 on 18 February; a webcam image from 0236 showed ejected incandescent material on the flanks. The lava dome on the crater floor was visible in satellite images and hadn’t significantly changed since the 27 January overflight. On 20 February a minor explosion was recorded at 1805, and a moderate explosion at 2331 ejected incandescent material onto the upper flanks. A series of five minor explosions were recorded at 0027, 0052, 0252, 0401, and 0529 on 21 February. Ash fell in Amecameca (19 km NW), in the State of Mexico, during 20-21 February. 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)