On 23 November INSIVUMEH reported that during the previous few days moderate explosions at Fuego generated shock waves that vibrated structures within 20 km. Ash plumes from the explosions rose 1.3 km above the cone in the summit crater and drifted 20 km W and SW, causing ashfall in areas downwind including Panimaché (8 km SW), El Porvenir (8 km ENE), Morelia (9 km SW), Santa Sofia (12 km SW), Sangre de Cristo (8 km WSW), Palo Verde Estate, and San Pedro Yepocapa (8 km NW). Incandescent material was ejected 150 m high, causing avalanches, some that traveled long distances in the Las Lajas (SE), Ceniza (SSW), and Seca (W) drainages and reached vegetated areas. During 24-25 November there were 12-15 weak-to-moderate explosions per hour, generating ash plumes that rose as high as 1.1 km and drifted 20-25 km W and SW. Shock waves continued to vibrate local structures, and ashfall was again reported in Panimaché, El Porvenir, Morelia, Santa Sofia, Sangre de Cristo, Palo Verde Estate, and San Pedro Yepocapa. Moderate-to-strong Vulcanian explosions on 26 November generated ash plumes that rose as high as 1.2 km and drifted N. The explosions were heard, and shock waves felt, mostly within 25 km, though some explosions were audible to residents of Guatemala City (city center is about 40 km ENE). Explosions continued the next day at a rate of 10-15 per hour. Ash plumes rose as high as 1.3 km and drifted 20-25 km W and SW. Incandescent material was ejected 200 m high, and avalanches of material descended multiple drainages. Ashfall was reported in areas downwind.

Geological Summary. Volcán Fuego, one of Central America's most active volcanoes, is also one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between Fuego and Acatenango to the north. Construction of Meseta dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at the mostly andesitic Acatenango. Eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH), Coordinadora Nacional para la Reducción de Desastres (CONRED)