INSIVUMEH reported that there were 10-18 explosions per hour recorded at Fuego during 2-8 October, generating ash plumes that rose as high as 1.1 km above the crater rim and drifted 10-25 km S, SW, W, and NW. Ashfall was reported in several areas downwind including Santa Sofía (12 km SW), Morelia (9 km SW), Panimaché I and II (8 km SW), Finca Palo Verde, San Pedro Yepocapa (8 km NW), and El Porvenir (8 km ENE). Explosions sometimes produced shock waves that rattled houses in nearby communities. Incandescent material was ejected 200-400 m high and caused avalanches of material that occasionally traveled long distances (reaching vegetated areas) down the Seca (W), Taniluyá (SW), Ceniza (SSW), Trinidad (S), El Jute (SE), Las Lajas (SE), and Honda ravines. Lava flows traveled 200 m down the Seca drainage on 6 October and were active in the Santa Teresa (W) drainage on 8 October. Lahars descended the Ceniza, El Mineral, and Seca drainages during 3-7 October, carrying tree branches, trunks, and blocks 1-3 m in diameter.

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)