INSIVUMEH reported that during 4-5 September incandescent material rose as high as 200 m above Fuego’s crater rim, and ash plumes rose 450 m and drifted W and SW. Sounds resembling train engines were constant and rumblings were heard six to nine times per hour. A 500-m-long lava flow was active in the Las Lajas (SE) drainage. Activity increased during the early afternoon on 5 September. The magnitude and number of explosion (6 per hour) increased, generating ash plumes that rose 850 m and drifted 12 km W and SW. The lava flow had grown to 1.2 km long. The rate of six explosion per hour continued on 6 September. Ash plumes rose 850 m and drifted 10 km W and SW, causing ashfall in Sangre de Cristo (8 km WSW), Panimache (8 km SW), and other nearby areas.

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)