INSIVUMEH reported that 1-6 explosions per hour were recorded at Fuego during 21-27 June, generating daily ash plumes that rose as high as 1.1 km above the crater rim and drifted as far as 30 km S, SW, W, and NW. The ash plumes were described as dense during 22-23 June and mostly gas with diffuse ash during 24-26 June. The explosions occasionally triggered weak-to-moderate avalanches that descended multiple ravines. Minor ashfall was reported on all days, except 21 June, in areas downwind including La Soledad (7 km N), El Porvenir (8 km SE), Panimanché I and II (8 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), Yucales (12 km SW), Finca Palo Verde (10 km WSW), Sangre de Cristo (8 km W), and Yepocapa (9 km WNW). Lahars descended the Ceniza (SSW) ravine on 21 June and the El Jute (ESE) ravine on 23 June.

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)