CENAPRED reported that during 12-18 June seismicity at Popocatépetl indicated continuing gas-and-steam emissions that sometimes contained small amounts of ash; cloud cover often prevented visual confirmation. During 12-13 June a total of about 45 minutes of low-amplitude harmonic and high frequency tremors were detected. An explosion at 1716 on 14 June produced an ash plume that rose 1.5 km above the crater. Another explosion at 1727 produced an ash plume that rose almost 3 km. The next day an explosion at 0716 generated an ash plume that rose 2 km. Explosions were also detected at 1610 and 1813.

During 14-17 June periods of low-amplitude harmonic tremor and high-frequency tremor continued to be detected. On 16 June an explosion at 0611 ejected incandescent tephra 500 m onto the N flank. An explosion on 17 June produced an ash plume that rose more than 4 km, and ejected incandescent tephra up to 2 km from the crater. Some of the high-temperature fallout caused small fires in grasslands on the flanks. Ashfall was reported in Tetela del Volcán (20 km SW), Ocuituco (24 km SW), Yecapixtla (31 km SW), Atlatlahucan (30 km WSW), Cuautla (43 km SW), Tlayacapan (40 km WSW), Yautepec (50 km WSW), Jiutepec (60 km WSW), and Xochitepec (70 km WSW) in Morelos state. Ash also fell in Ecatzingo (15 km SW), Atlautla (17 km W), and Ozumba (18 km W) in México state. The Alert Level remained at Yellow, Phase Two.

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.

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)