Volcán Popocatepetl, whose name is the Aztec word for smoking mountain, towers to 5426 m 70 km SE of Mexico City to form North America's 2nd-highest volcano. The glacier-clad stratovolcano contains a steep-walled, 250-450 m deep 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 south of the volcano. The modern volcano was constructed to the south of the late-Pleistocene to Holocene El Fraile cone. Three major plinian eruptions, the most recent of which took place about 800 AD, have occurred from Popocatepetl 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 precolumbian time.
Popocatepetl, the second highest volcano in Mexico, is a giant stratovolcano, 70 km (~45 miles) southeast of downtown Mexico City, and 45 km (~30 miles) southwest of the city of Puebla.
Popo - as many people call it rather than struggling with its full name (Popo-cat-e-petal) - became active just before Christmas after five decades of quiet. During the last two years the volcano has frequently had a small column of steam rising from its summit crater. After midnight on December 21, 1994 a series of earthquakes signaled that eruptions had started. That morning a gray ash cloud was visible over the top of the volcano, and ash fell on Puebla.
During the afternoon, the eruptions increased. Because most of the ash was blowing to the east, civil defense authorities decided to evacuate 19 villages (31,000 people) east of Popo. Moderate eruptions have continued, and according to newspapers the total number of evacuees was about 75,000 people by December 26. The United States Geologic Survey has sent a team of volcano experts to Mexico to help Mexican scientists evaluate what the volcano may do in the near future. The volcano has been quite for more than a week now.
Popo is one of the most active volcanoes in Mexico, having had 15 eruptions since the arrival of the Spanish in 1519 AD. The Aztec Indians who lived in Central Mexico recorded additional eruptions in 1347 and 1354. Most of the eruptions in the past 600 years were relatively mild, with ash columns rising only a few kilometers above the summit.
Volcanologists have studied Popo because most volcanoes tend to have future eruptions that are like their earlier ones. Thus, the volcano's past history helps us prepare for possible future activity. One very important reason to try to predict future eruptions is that more than 20 million Mexican people live close enough to the volcano to be threatened by its eruptions.
Additional information about Popocatepetl is available on the homepage of the Cascade Volcano Observatory .
Popocatepetl Volcano News provides additional information about the eruption.
CENAPRED , additional disaster preparation information.
Sources of Information:
Summary by Charles Wood, 26 December, 1994 and updated 4 Jan., 1995.
Global Volcanism Program, Department of Mineral Sciences, National Museum of Natural History - Room E-421, MRC 0119, PO Box 37012, Smithsonian Institution, Washington DC 20013-7012
Smithsonian Institution E-Mail Report by Servando De la Cruz-Reyna (Univ. of Mexico) on Dec 23, 1994.
Cantagrel, JM, A Gourgaud & C Robin (1984) Repetitive mixing events and Holocene pyroclastic activity at Pico de Orizaba and Popocatepetl (Mexico). Delgado, H., 1996, Popo's event, VOLCANO ListServ, October 29, 1996
Global Volcanism Network report posted in Volcano homepage of Michigan Tech University.
Simkin, T., and Siebert, L., 1994, Volcanoes of the World: Geoscience Press, Tucson, Arizona, 349 p.