On 1 June, five moderately strong explosions occurred at Fuego with gas-and-ash plumes rising up to 2 km above the summit. Incandescent avalanches of material from these explosions occurred in the Santa Teresa and Río Taniluyá ravines. This pulse of activity was preceded by half an hour and followed by two hours of explosions producing steam plumes rising up to ~0.5 km above the summit. On 6 June, frequent small explosions produced gas plumes that rose to ~0.5 km above the summit and less frequent explosions produced gas-and-ash plumes that rose to ~1.0 km above the summit. Incandescent avalanches from these explosions occurred in the Santa Teresa and Ceniza ravines. A hot lahar, followed 45 minutes later by a smaller lahar, occurred in the Zanjón Barranca Seca ravine on 6 June. Moderate explosions continued on 7 June, producing small gas-and-ash plumes to ~0.5 km above the summit.

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)