CENAPRED reported that during 10-16 April seismicity at Popocatépetl indicated continuing gas-and-steam emissions that sometimes contained ash. Incandescence from the crater was observed at night and sometimes increased in conjunction with emissions. On 10 April gas-and-steam plumes rose 800 m above the crater and drifted ESE, and ash plumes rose 900 m and also drifted ESE. During 11-13 April gas-and-ash plumes rose 500 m and drifted NE. An explosion on 13 April produced a steam-and-ash plume that rose 400 m and drifted NE. Ashfall was reported in the towns of San Nicolas de los Ranchos (15 km ENE) and Huejotzingo (27 km NE), and in the northern part of Puebla (40 km E). On 14 April a period of tremor was accompanied by continuous emissions of dense steam-and-gas plumes with small amounts of ash that rose as high as 1 km and drifted NE. The next day ash plumes rose 1.5 km above the crater, and incandescent tephra ejected from the crater landed 400 m away on the NE flank. On 16 April gas-and-steam plumes rose 1 km and drifted NE. 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)