INSIVUMEH reported that eruptive activity continued at Fuego during 23-31 January. Explosions were recorded daily, averaging 2-9 per hour on most days when counts were reported; daily reports were not available on 29 and 30 January. The explosions generated gas-and-ash plumes that rose as high as 1.2 km above the crater rim and drifted as far as 30 km in multiple directions. Explosions caused frequent block avalanches that descended various drainages including the Ceniza (SSW), Seca (W), Taniluyá (SW), and Las Lajas (SE) and reached vegetated areas. The explosions also ejected incandescent material 100-400 m above the summit on most of the days. Ashfall was reported during 25-26 and 27-28 January in areas downwind including Yepocapa (12 km SW), Panimache I and II (8 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), Finca Asuncion (12 km SW), La Rochela (8 km SSW), Finca Ceilán (9 km S), and San Andrés. Ashfall was forecasted to fall in communities to the N, NW, SW, and S on the other days. Weak rumbling sounds and shock waves were frequently reported.

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.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)