Report on Popocatepetl (Mexico) — 25 July-31 July 2018
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 25 July-31 July 2018
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2018. Report on Popocatepetl (Mexico). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 25 July-31 July 2018. Smithsonian Institution and US Geological Survey.
19.023°N, 98.622°W; summit elev. 5393 m
All times are local (unless otherwise noted)
CENAPRED reported that each day during 25-31 July there were 24-42 steam-and-gas emissions from Popocatépetl, and nightly crater incandescence. Explosions were detected almost every day: five on 26 July; nine on 27 July; one on 28 July; three on 30 July. A series of gas-and-ash emissions began at 0307 on 31 July and lasted for 215 minutes. Ejected incandescent tephra landed on the flanks. The gas-and-ash plumes rose 2 km above the crater rim and drifted WSW, causing ashfall in Tetela del Volcán, Yecapixtla, Tlalnepantla, and Totolapan (Morelos state), and in Amecameca, Acuautla, Ecatzingo, Ozumba, and Tepetlixpa (Mexico state). The Alert Level remained at Yellow, Phase Two.
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.