INSIVUMEH reported that during 13-14 June explosions at Fuego generated shock waves detected within 10 km, and block avalanches descended the Ceniza (SSW), Taniluyá (SW), Santa Teresa (SW), and Trinidad (S) ravines. On 18 June heavy rain triggered a 20-m-wide, 1.5-m-deep lahar that traveled down the El Jute (SE) ravine, carrying tree trunks and blocks as large a 2 m in diameter. Explosions during 18-20 June produced ash plumes that rose as high as 950 m above the crater and drifted 8-12 km S, SW, and W. Ashfall was noted in areas downwind including Morelia (9 km SW), Santa Sofía (12 km SW), Finca Palo Verde, El Porvenir (8 km ENE), Sangre de Cristo (8 km WSW), and Panimaché I and II (8 km SW). Incandescent material was ejected 100-200 m above the crater rim, and caused avalanches of material that traveled into the Ceniza, Taniluyá, Trinidad, and Santa Teresa drainages.

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)