INSIVUMEH reported that during 23-26 April explosions from Fuego generated ash plumes that rose 250-600 m above the crater and drifted at most 10 km W, SW, S, and SE. Incandescent material was ejected 100-200 m above the crater. In a special bulletin on 25 April INSIVUMEH noted that the energy of the explosions had increased, producing rumblings and shock waves that vibrated structures in Panimaché, Morelia, and Sangre de Cristo, as far as 10 km S and SW. A 300-m-long lava flow was active on the S flank in the Trinidad drainage. On 26 April a lava flow in the Taniluya drainage (SW) traveled as far as 400 m. On 28 April activity again increased and 700-m-long lava flows were active in the Taniluya and Ceniza drainages. Incandescent block avalanches reached vegetated areas. Cloud cover prevented observations of the crater. On 29 April explosions generated ash plumes that rose 550 m above the crater and drifted 10 km SSW. Lava flows remained active.

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)