Report on Popocatepetl (Mexico) — 22 August-28 August 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 22 August-28 August 2012
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2012. Report on Popocatepetl (Mexico). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 22 August-28 August 2012. Smithsonian Institution and US Geological Survey.
19.023°N, 98.622°W; summit elev. 5393 m
All times are local (unless otherwise noted)
CENAPRED reported that during 22-28 August seismicity at Popocatépetl indicated continuing gas-and-steam emissions that may have contained ash; cloud cover often prevented visual observations of the volcano. During 22-28 August gas-and-steam plumes rose from the crater, and drifted WSW, W, and WNW during 22-24 August. Incandescence from the crater was observed at night during 23-26 August. Bluish steam-and-gas plumes rose from the crater on 27 August. At 2233 an explosion produced an ash plume and ejected incandescent tephra that fell back into the crater. More robust emissions that rose 500 m were sometimes accompanied by incandescence from the crater. Later a plume rose 1.5 km. The next day bluish steam-and-gas plumes rose 1.2 km. The Alert Level remained at Yellow, Phase Three.
Geologic Background. 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.