Report on Popocatepetl (Mexico) — 25 July-31 July 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 25 July-31 July 2001
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2001. Report on Popocatepetl (Mexico). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 25 July-31 July 2001. Smithsonian Institution and US Geological Survey.
19.023°N, 98.622°W; summit elev. 5393 m
All times are local (unless otherwise noted)
Several small-to-moderate sized emissions occurred at Popocatépetl that were mainly composed of steam, gas, and small amounts of ash. The Washington VAAC received a pilot report on 24 July at 1100 of an ash cloud ~5.5 km above the volcano drifting to the W. On 23 July CENAPRED reduced the Alert Level from Yellow Phase III to Phase II because volcanic activity was at lower levels than it was in December 2000 when the Alert Level was originally raised.
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.