INSIVUMEH reported on 12 October that explosions from Fuego produced ash plumes that rose to altitudes of 4.2-4.8 km (13,800-15,700 ft) a.s.l. and drifted W and SW. Ashfall was reported from areas to the W. The explosions were accompanied by rumbling noises, degassing sounds, and shock waves detected up to 15 km away. The Washington VAAC reported a thermal anomaly along with ash plumes drifting W and NW that were visible on satellite imagery during 15-16 December. INSIVUMEH reported that on 17 December, Fuego returned to normal levels after the 15-16 December eruption. A few explosions were registered by the seismic network and ash plumes rose to altitudes of 4.5 km (17,800 ft) a.s.l. plumes drifted S and SW.

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: Washington Volcanic Ash Advisory Center (VAAC), Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)