INSIVUMEH reported that eruptive activity continued at Fuego during 11-18 June. Daily explosions were recorded by the seismic network, averaging 3-9 per hour on most days, when counts were reported. The explosions generated gas-and-ash plumes that rose as high as 1.1 km above the crater rim and drifted as far as 30 km in multiple directions. Weather conditions often prevented visual observations during the second half of the week, though explosions and block avalanches were recorded by instruments and could often be heard. The explosions produced block avalanches that descended various drainages including the Ceniza (SSW), Seca (W), Taniluyá (SW), and Las Lajas (SE), and Honda (E), and often reached vegetated areas. Weak rumbling sounds and shock waves that rattles nearby houses and buildings were reported on most days. Ashfall was reported during 11-12 and 15-16 June in areas downwind including Acatenango (8 km E), La Soledad (11 km N), Parramos (18 km NNE), Patzicia (17 km NNW), and Yepocapa (8 km NW). Ashfall was forecast for areas downwind on some of the other days. The explosions also ejected incandescent material up to 100-400 m above the summit during 11-13 and 16-17 June. On 12 June lahars descended the Las Lajas and Ceniza drainages, carrying tree branches, trunks, and blocks as large as 1.5 m in diameter.

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)