Report on Popocatepetl (Mexico) — 5 November-11 November 2003
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 5 November-11 November 2003
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2003. Report on Popocatepetl (Mexico). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 5 November-11 November 2003. Smithsonian Institution and US Geological Survey.
19.023°N, 98.622°W; summit elev. 5393 m
All times are local (unless otherwise noted)
This tall volcano is commonly obscured by clouds and scientists are then forced to rely on seismicity detected by the monitoring network to define the number of "daily exhalations." Daily exhalations during the week of 5-11 November 2003 typically stood at ~5. By comparison, during March 1996 the daily exhalations reached ~180. Other monitored parameters during 5-11 November also indicated relative stability. Scientists also consider the energy released by the exhalation-related seismicity, and not surprisingly, this also stood much higher during mid-1996. A 17 October 2003 flight over the volcano allowed scientists to see into the crater; the crater floor looked comparatively flat, without signs of a rising dome. Good visibility on 6 November brought little sign of fumarolic steam rising from the volcano. No aviation ash advisories were issued for Popocatépetl during this week.
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.