An eruption began at Fuego on 27 December around 0545 and produced lava flows that traveled down Taniluya (SW) and Seca (W) ravines, initially extending ~800 m and 1,200 m, respectively. At 0602 a pyroclastic flow descended Seca Ravine, producing a S-drifting column of ash that rose to a height of ~2 km above the volcano (or 18,900 ft a.s.l.). Ash fell to the S of the volcano in the port of San Jose. Later that day, the lava flows reached lengths of 1.2 and 1.3 km, and pyroclastic flows traveled 1.8 and 2 km down the Taniluya and Seca ravines, respectively. Lava flows also traveled W toward Santa Teresa ravine, and SE towards Jute and Lajas ravines. A small amount of ash fell W and SW of the volcano in the villages of Panimaché (~7 km SSW), Morelia, Santa Sofía, and Los Tarros.

Volcanic activity continued through 28 December, with incandescent lava clots hurled ~75 m high, lava flows traveling down the volcano's flanks, and a dark gas-and-ash plume rising to ~1 km above the volcano (or 15,600 ft a.s.l.). Avalanches of volcanic material spalled from lava-flow fronts. On the 29th, lava only flowed in Santa Teresa ravine, reaching ~600 m. Moderate explosions continued through 3 January, depositing small amounts of ash in Panimaché village. According to a news article, none of the ~250,000 residents from the 78 communities near the volcano were evacuated.

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), Reuters