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Report on Popocatepetl (Mexico) — October 2000


Bulletin of the Global Volcanism Network, vol. 25, no. 10 (October 2000)
Managing Editor: Richard Wunderman.

Popocatepetl (Mexico) Increased gas-and-ash emissions in early November elevates hazard status

Please cite this report as:

Global Volcanism Program, 2000. Report on Popocatepetl (Mexico) (Wunderman, R., ed.). Bulletin of the Global Volcanism Network, 25:10. Smithsonian Institution.



19.023°N, 98.622°W; summit elev. 5393 m

All times are local (unless otherwise noted)

This report covers the period from 22 August to 4 November 2000 (table 13). Volcanic activity during this period generally was similar to that for the preceding summer months (BGVN 25:07). Steam-and-gas exhalations occurred frequently, with daily variations in intensity and duration. The reported number of daily exhalations varied from only a few to as many at 140 (12 September). Some exhalations included ash, several of the larger ones generated ash plumes 5 or 6 km above the crater and caused ash falls on towns downwind, including NW-flank towns. On 4 September ashfall reached the S limit of the capital. Seismic tremor was also common, both harmonic and high frequency, some of low amplitude and duration and others lasting from 30 minutes to several hours.

Table 13. Summary of Popocatépetl's activity during 22 August to 4 November 2000. Exhalations were seismically detected. The symbol x means tremors were reported (for stated duration). Courtesy of CENAPRED.

Date Exhalations Description of other activity
22-23 Aug 2000 increasing --
24 Aug 2000 steady --
25 Aug 2000 increasing --
26-27 Aug 2000 steady --
28 Aug 2000 increasing --
29 Aug 2000 decreasing One VT event; harmonic tremor
30-31 Aug 2000 decreasing --
01 Sep 2000 decreasing --
02 Sep 2000 increasing 3-km-high plume; harmonic tremor
03 Sep 2000 decreasing --
04 Sep 2000 increasing One (M 1.8) VT event; plume; 25 minutes of harmonic tremor
05 Sep 2000 -- Harmonic tremor
06 Sep 2000 steady Two (M less than 2) VT events; harmonic tremor
07 Sep 2000 steady One (M 2.1) VT event
08-09 Sep 2000 steady Harmonic tremor
10-12 Sep 2000 increasing Harmonic tremor
13 Sep 2000 decreasing Harmonic tremor
14 Sep 2000 steady Harmonic tremor
15 Sep 2000 increasing --
17 Sep 2000 decreasing One (M 2.5) VT event; harmonic tremor
18 Sep 2000 decreasing Harmonic tremor; 12.7 t/d SO2
19-21 Sep 2000 steady --
22 Sep 2000 steady One (M 2.8) VT event; 2-km-high plume
23 Sep 2000 decreasing Two (M ~ 2) VT events
03 Oct 2000 increasing 6-km-high plume; harmonic tremor
04 Oct 2000 steady 1-km-high plume
05 Oct 2000 decreasing --
06 Oct 2000 steady Harmonic tremor
09-10 Oct 2000 steady Harmonic tremor; high-frequency tremor
15 Oct 2000 steady --
16 Oct 2000 increasing Four (M 2.4) VT events; 2-km-high plume; explosive exhalation
17 Oct 2000 decreasing High-frequency tremor
18 Oct 2000 increasing 3 hours of high-frequency tremor
19 Oct 2000 steady High-frequency tremor
20 Oct 2000 increasing --
21 Oct 2000 steady Harmonic tremor; high-frequency tremor
22 Oct 2000 steady Two VT events
23 Oct 2000 increasing SO2 emission
24 Oct 2000 steady Harmonic tremor; high-frequency tremor
25 Oct 2000 steady High-frequency tremor
26 Oct 2000 increasing --
27 Oct 2000 increasing High-frequency tremor
28 Oct 2000 steady 2-km-high plume; 90 minutes of high-frequency tremor; decreased SO2 emission
29 Oct 2000 increasing 3-km-high plume
30 Oct 2000 steady --
31 Oct 2000 decreasing --
01 Nov 2000 steady Harmonic tremor; high-frequency tremor
02 Nov 2000 -- One (M 3.1) VT event; 3-km-high plume; 30 minutes of high-frequency tremor
03 Nov 2000 -- Four (M 2.2-3.0) VT events; plume; Alert level raised

Volcano-tectonic (VT) earthquakes registered on 29 August; 4, 6, 7, 17, 22, 23, September; 16, 22, 27 October; and 2, 3 November. Most of these were M <=2.0 but those occurring on 22 September, 16 October, and in early November were M 2.4-3.1. The latter two periods also coincided with explosive exhalations as described below.

On 16 September, a small dome (very small compared to the one that grew in 1997) was observed during a flight over the crater. On 18 September, an SO2 level of 12,700 tons/day was registered. The VT event on 22 September was registered 20 km SE of the volcano. An explosive exhalation at 0520 on 16 October sent incandescent fragments ~1 km to the NE. As noted above, four VT earthquakes preceded this exhalation, one (the largest) was M 2.4. A second explosive exhalation occurred later that day at 1142 although no incandescent fragments were confirmed.

On 29 October, 102 exhalations registered and, at 1710, a moderately large exhalation produced an ash plume that rose to 3 km above the crater and moved ~25 km WNW. On 2 November, the volcano had an increase in activity and at 1717 there was a moderate exhalation followed by 30 minutes of high-frequency tremor. The event sent an ash plume 3 km above the crater; ash fell on several towns. At 1827 a VT event of M 3.1 was registered SE of the volcano. Then, between 1300 and 1630 on 3 November, four VT events occurred; these M 2.2-3.0 events were located below the crater. Later that day, the Scientific Committee discussed the increased activity over the previous few days and, in conjunction with the Civil Protection Authorities, decided to change the hazard status to Yellow III, recommending further that the security radius around the volcano be increased to 10 km (from the radius of 7 km that had prevailed for many months).

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.

Information Contacts: Centro Nacional de Prevencion de Desastres (CENAPRED), Delfin Madrigal 665, Col. Pedregal de Santo Domingo, Coyoacán, 04360, México D.F. (URL: https://www.gob.mx/cenapred/); Washington VAAC, Satellite Analysis Branch (SAB), NOAA/NESDIS E/SP23, NOAA Science Center Room 401, 5200 Auth Road, Camp Springs, MD 20746, USA (URL: http://www.ssd.noaa.gov/).