INSIVUMEH reported that on 4 November, there was an increase in moderate and strong explosions generating plumes of ash up to 4,500 m a.s.l. The plume extended 10 km and drifted S and SW. Rumbling sounds were strong enough to shake zinc roofs and windows in the towns of Panimaché, Morelia, and Panimaché II. Weak degassing sounds were continuous and resembled the sound of a locomotive train. Pulses of incandescent ejections reached 125-200 m above the summit and caused weak-to-moderate avalanches within the crater. A lava flow that moved into the Trinidad drainage extended 100 m and also generated avalanches. Within the Ceniza drainage, incandescent avalanches traveled ~500 m. CONRED reiterated that the Alert Level remained at Yellow.

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)