Report on Popocatepetl (Mexico) — June 1999
Bulletin of the Global Volcanism Network, vol. 24, no. 6 (June 1999)
Managing Editor: Richard Wunderman.
Popocatepetl (Mexico) Small exhalations, minor fumarolic activity, and variable seismicity
Please cite this report as:
Global Volcanism Program, 1999. Report on Popocatepetl (Mexico). In: Wunderman, R (ed.), Bulletin of the Global Volcanism Network, 24:6. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199906-341090.
19.023°N, 98.622°W; summit elev. 5393 m
All times are local (unless otherwise noted)
The low level of activity displayed in May continued, with small exhalations and minor fumarolic emissions until 12 June. However, seismic activity increased on 12 June and continued for the next 10 or 11 days. At 1209 and 1600 on 12 June, two M 2.2 volcano-tectonic events occurred under the crater and SW of the volcano. At 1542 on 15 June, a large earthquake (M 6.7) centered between the states of Puebla and Oaxaca did not affect the volcano. Bad weather had obstructed visibility earlier, but that afternoon observers saw small fumarolic emissions of steam and gas.
Seismicity increased on 16 June as several volcano-tectonic events were recorded in the morning, most with magnitudes between 2.5 and 3 and two larger ones with M >3. These events were located 4-7 km below the summit crater. The last event occurred at 0206 on 17 June. This seismicity did not produce any important external manifestations except a small exhalation on the morning of 17 June accompanied by a light ash puff blown to the W.
On 21 June two earthquakes in Guerrero did not effect the volcano. No other events were reported for the month and by 30 June the radius of restricted access was reduced to 5 km from the 7 km previously recommended.
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.
Information Contacts: Servando De la Cruz-Reyna1,2, Roberto Quaas1,2; Carlos Valdés G.2, and Alicia Martinez Bringas1. 1-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/); 2-Instituto de Geofisica, UNAM, Coyoacán 04510, México D.F., México.