INSIVUMEH reported that eruptive activity continued at Fuego during 5-11 July. Steam-and-gas emissions rose 300-540 m above the crater rim and drifted SW, W, and NW. Daily counts of weak and sometimes moderate explosions averaged 2-7 per hour. Explosions triggered weak and moderate avalanches that descended the Honda (E), El Jute (ESE), Las Lajas (SE), Trinidad (S), Ceniza (SSW), and Seca (W) ravines. Sometimes explosions were accompanied by ash plumes that rose as high as 1 km above the crater and drifted as far as 20 km SW, W, and NW. Degassing sounds (similar to a jet engine) lasting 1-2 minutes were reported on most days. Minor ashfall was reported in areas downwind, including El Porvenir (8 km SE), Panimaché I (7 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), Panimaché II (8 km WSW), Finca Palo Verde (10 km WSW), Sangre de Cristo (8 km W), and Yepocapa (9 km WNW).

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)