Activity during 6-7 June remained at normal low levels, with minor gas-and-steam emissions, tremor, and a few small volcano-tectonic earthquakes at around 6 km depth below the crater. Increased emissions on 8 June sometimes included small amounts of ash. An explosion on 9 June at 0424 sent ash to an unknown height. Moderate activity continued through the next morning and decreased slightly. The Mexico City MWO reported an ash emission on 11 June at 1100 that rose 7.6 km a.s.l., but it was not seen on satellite imagery. The MWO warned of another ash emission on 12 June at 1648, but cloudy conditions prevented a height estimate. Typical low-to-moderate activity continued through 13 June, with the Yellow alert level unchanged.

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