The Centro Nacional de Prevención de Desastres (CENAPRED) reported that eruptive activity continued at Popocatépetl during 25 February-4 March. The seismic network recorded 11-31 long-period events per day on most days, accompanied by steam-and-gas emissions; there were 143 such events during 2-3 March. The seismic network also recorded daily tremor, often characterized as low-amplitude harmonic tremor, with periods lasting 34 minutes to as long as two hours and 23 minutes. One volcano-tectonic was detected during 28 February-1 March, and 17 minutes of high-frequency tremor were detected during 1-2 March. According to the Washington VAAC ash plumes were visible in webcam images on 25 and 27 February rising 5.8-6.4 km (19,000-21,000 ft) a.s.l. (around 1 km above the summit) and drifting SE. The Alert Level remained at Yellow, Phase Two (the middle level on a three-color scale) and the public was warned to stay 12 km away from the crater.

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.

Sources: Centro Nacional de Prevencion de Desastres (CENAPRED), Washington Volcanic Ash Advisory Center (VAAC)