Report on Popocatepetl (Mexico) — 17 January-23 January 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 17 January-23 January 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, 17 January-23 January 2001. Smithsonian Institution and US Geological Survey.
19.023°N, 98.622°W; summit elev. 5393 m
All times are local (unless otherwise noted)
In addition to multiple exhalations, Popocatépetl produced both pyroclastic flows and mudflows that traveled several kilometers downslope. The Washington VAAC reported that at ~1500 on 14 January a small exhalation sent ash to ~7.6 km a.s.l. They also reported that a larger explosive eruption occurred at ~1615 on 22 January that sent ash to 6-12 km a.s.l. CENAPRED reported that the eruption produced pyroclastic flows that descended ~4-6 km down several gorges on the N and NW flanks of the volcano. Ash was deposited on Santiago Xalitzintla, Atlixco, Tecamachalco, Tetela, and part of Puebla. A small (10 cm thick and 2 m wide) mudflow traveled up to 8 km from the town of Santiago Xalitzintla down the Huiloac gorge. Scientists believe the pyroclastic flows melted a small portion of the glacier near the volcano's summit and the glacial meltwater mixed with ash. Another explosive eruption that occurred at 1915 the same day was followed by ongoing ash exhalations through 23 January. An eruption at 1041 on 23 January sent ash to ~9.1 km a.s.l. that blew to the S. Several small explosions and continuous ash emissions followed. The volcano remained at Alert Level Yellow Phase III with a 12 km security radius.
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.