INSIVUMEH reported that during 28-30 November explosions at Fuego produced ash plumes that rose at most 1.2 km above the crater and drifted as far as 25 km S, SW, and W. Shock waves from some of the explosions rattled structures near the volcano. Incandescent material was ejected 100-150 m above the crater duirng 29-30 November. Ashfall was reported in Panimaché I and II (8 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), and surrounding communities.

In a special bulletin issued on 1 December, INSIVUMEH reported that activity remained similar to the previous few days, characterized by periods of more frequent and intense explosions observed 6-8 times per hour. Dense gray ash plumes rose almost 1.3 km and drifted 20 km W and SW. Ash fell in Morelia, Santa Sofía, Panimaché, and Yepocapa. Some explosions were audible up to 30 km away. Shock waves vibrated structures on the S and SW flanks. Incandescent blocks descended multiple drainages. During 1-2 December explosions generated ash plumes that rose 850 m and drifted 15 km 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.

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