CENAPRED reported that eruptive activity continued at Popocatépetl during 21-27 February. The seismic network recorded daily periods of high-frequency, low-amplitude tremor that lasted from about 90 minutes to almost 22 hours. The Washington VAAC reported that daily ash plumes visible in webcam and satellite images generally rose to 5.2-6.7 km (17,000-22,000 ft) a.s.l. and drifted predominantly E, SE, S, and SW. The ash emissions were continuous for periods of time with remnant ash continuing to be visible in subsequent satellite images, drifting 75-140 km before dissipating. At 1151 on 24 February a dense ash plume rose to 7.6 km (25,000 ft) a.s.l. and drifted ENE; the plume was visible in satellite images the next day drifting almost 225 km SE. Several ash emissions lasting 1-2 hours each were visible in webcam and satellite images during 26-27 February.

Based on information from El Centro Nacional de Comunicación y Operación de Protección Civil (CENACOM), CENAPRED noted that minor ashfall was reported in Hueyapan (17 km SSW), Tetela del Volcán (20 km SW), and Jiutepec (59 km SW) in the state of Morelos on 21 February and in the municipalities of Jiutepec (60 km WSW), Atlatlahucán (30 km WSW), Cuautla (43 km SW), Tlaltizapan (65 km SW), and Ciudad Ayala in Morelos, and in Huaquechula (30 km SE) and Tlapanalá (39 km SE), Puebla, on 22 February. Minor ashfall was reported in the municipalities of Hueyapan, Yecapixtla (30 km SW) and Tetela del Volcán, Morelos; in Ixtacuixtla, Panotla, Tepetitla (36 km NE), Nativitas (40 km NE), Zacatelco (45 km NE), Santa Apolonia Teacalco (40 km NE), San Damián Texóloc (45km NE), Tetlahuaca (40 km NE), Zacatelco (45 km NE), Xicohtzingo (40 km ENE), Papalotla (62 km NNW), Tenancingo (47 km ENE), Santa Catarina Ayometla (47 km ENE), Magdalena Tlaltelulco (53 km NE), San Francisco Tetlanohcan (55 km NE), and Teolocholco (51 km ENE), Tlaxcala; in Iztacalco (62 km NW), Iztapalapa (59 km NW), and Coyoacán (65 km WNW), Mexico City; and finally in Atlautla (16 km W), Ayapango (21 km NW), Ecatzingo (15 km SW), Chalco (44 km NW), Tenango del Aire (29 km NW), Temamatla (32 km NW), Ozumba (18 km W), Tepetlixpa (20 km W), Tlalmanalco (30 km NW), and Amecameca (20 km NW), State of Mexico on 27 February. The Alert Level remained at Yellow, Phase Two (the middle level on a three-color scale) and the public was warned to stay 12 km away from the crater.

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.

Sources: Centro Nacional de Prevencion de Desastres (CENAPRED), Washington Volcanic Ash Advisory Center (VAAC)