Based on INSIVUMEH notices, CONRED reported that at 1345 on 25 January a Strombolian phase began at Fuego. Weak-to-moderate explosions generated ash plumes that rose 750 m above the crater rim and drifted 10 km W and SW. Lava fountains rose 200 m above the crater rim and fed lava flows that traveled 1 km SSW down the Ceniza drainage. Avalanches of material advanced more than 300 m down the Ceniza and Trinidad (S) drainages into vegetated areas. Ash fell on the SW and W flanks. The report also noted that a previous Strombolian phase had begun on 3 January.

INSIVUMEH reported that during 27-31 January explosions generated ash plumes that rose 500-900 m and drifted 5-10 km W, SW, S, and SE. Avalanches of material descended the Ceniza, Trinidad, and Santa Teresa (W) drainages.

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