On 22 December, the Washington VAAC reported that an ash plume from Fuego observed in satellite imagery drifted 28 km NW. INSIVUMEH reported that on 23 December explosions produced ash plumes that rose 600-1,200 m above the crater and drifted 10-15 km SE. Explosions the next day generated ash plumes 400 m above the crater. Incandescent material was ejected 100 m above the crater at night during 27-28 December. On 28 December ash plumes from explosions rose as high as 500 m above the crater and drifted more than 5 km S and SW. Avalanches descended multiple 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: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center (VAAC)