During 30 July-5 August, INSIVUMEH reported weak to moderate explosions at Fuego with incandescent blocks expelled 100-200 m above the crater accompanied by minor gray ash 300-400 m above the crater that drifted S. Shock waves from those explosions produced rumbling that rattled structures up to 4 km from the volcano. On most days, weak to moderate avalanches of blocks moved down the flanks towards Taniluya, Ceniza and Santa Teresa canyons. Gray to white plumes rose 4.2-4.6 km (13,800-15,100 ft) a.s.l. and drifted 9-12 km W and SW. Ashfall was reported in villages of Yepocapa, Finca La Conchita, Sangre de Cristo, Morelia and Panimaché.

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)